Math-X

Prime Numbers

2010-05-18T04:39:00.000-07:00

Definitions

A prime number is a number that has only two factors, 1 and itself. A composite number it is a number with factors other than 1 and itself. Exceptional Case: The number 1 is neither prime nor composite by definition.

Exercise
Determine whether the following numbers are prime or composite. If it is composite, list out its factors.

1) 19 2) 22

prime composite - 1; 2; 11; 22

3) 37 4) 51

prime composite - 1; 3; 17; 51

Are there any even numbers that are prime?

Yes, 2 is the only prime number that is even. Think about why. How can we nd prime numbers?

We can fi nd them using the method called Sieve of Eratosthenes.

Instructions:
1. Cross o 1 since it is not prime.
2. Find the first prime number (2) and circle it.
3. Go through the rest of the chart and cross o all of the multiples of two.
4. Go back to the beginning of the chart and nd the rst number that is not crossed o . Circle it, it is prime. Then go through the rest of the chart, crossing o the multiples of this number.
5. Repeat step 4, until every number in the chart is either circled or crossed o .
6. The numbers that are circled are the prime numbers.

Symmetry

2010-04-27T21:24:00.000-07:00

The following data related to folding and round symmetry.
If a folded up into two, so the folds of which one can cover the other parts correctly, then the symmetry is said to have folded up. If a flat wake, and can be played through the exact center occupies the first place has a symmetry is said to wake up the play. Number of those occupying the place originally built in a single round of the play shows the number of symmetry.

Notes: Total Fold Symmetry (SL), number of symmetries (SP)1. Equilateral triangle, SL = 3, SP = 32. Isosceles triangle, SL = 1, SP = 13. Rectangle, SL = 2, SP = second4. Square, SL = 4, Sp = 45. parallelogram, SL = -, SP = 16. Loop, SL = infinity, SP = infinity7. Isosceles trapezoid, SL = 1, SP = 18. Hexagon, SL = 4, SP = 69. Kite, SL = 1, SP = 210. Rhombus, SL = 4, SP = 4

Congruency

2010-04-27T21:20:00.000-07:00

1. Triangle Two triangles congruent to say if the angles are equal and the comparison of the sides the same length.
2. Quadrilateral (Rectangular and Square)] Two congruent rectangles be said when comparing the sides the same length.
3. Trapezoid, Parallelogram
Two trapezoid congruent or parallelogram said when comparing the sides the same length and in the same location angles of equal size.
4. Rhombus, kite Two rhombus or a kite is said to congruent if the sides the same length and the angles which in the same lcoation equally.

Algebra Part 1

2010-02-19T03:32:00.000-08:00

The seventh grade has 10 days to sell tickets to a talent show. The students figure that each day they will sell 20 fewer tickets than the day before. How much must they sell the first day if they want to sell 900 tickets in all ?

Answer:
180 tickets

At Raymond's Bakery, cookies are sold as follows: $.30 each for the first half dozen, $.25 each for the next half dozen, and $.10 each for any additional cookies. What change would you get back $10.00 after buying 3 dozen cookies ?

Answer:
$4.30

Problem Solving Practise II

2010-02-18T06:03:00.000-08:00

Problem 1:
Ms. Johnson fills her car with gas every sixth day. Mr. Martinez fills his car with gas every eight day. They both filled their gas tanks today. How many days will it be until they next fill their cars on the same day ?

Answer: 24 days

Problem 2:
A radio station gave free t-shirt to listeners during a three day promotion. The disk jockey gave away half of the shirt plus one during the first day, half of the remaining shirts plus one during the third day. At the end of the third day there was one shirt remaining. How many shirts were there at beginning of the promotion ?

Answer: 22 shirts

How many triangles ?

2010-02-16T05:41:00.000-08:00

How many triangles are shown ?

Answer:
13 triangles

Counting Numbers

2010-02-16T05:24:00.000-08:00

Counting numbers like 6, 7, 8, 9, and 10 are called consecutive. Find six consecutive counting numbers with a sum of 81 !

Answer:
11, 12, 13, 14, 15, 16

Problem Solving Practise

2010-02-16T05:16:00.000-08:00

1. The Martin Luther King School library has 8 tables and 42 chairs. There are several small tables with 4 chairs each and some large tables with 6 chairs each. How many tables of each type are in the library ?

Answer: 3 small and 5 large

2. A display of oil cans in an auto part store is stacke so that each row has one less can than the row below it. If there are 21 cans in the display, how many rows of cans are there ?

Answer: 6 rows

Average

2010-01-19T01:11:00.000-08:00

Question:
Find the average of the following set of numbers to the nearest whole number: 54, 38, 49, adn 44.

Answer:
46

Math Problem

2010-01-19T01:07:00.001-08:00

A farmer has a fox, a chicken, and a bag corn. He must ferry all three across a river in a boat tha will hold only himself and one other item. The chicken cannot be left alone with either the fox or the corn. How will the farmer take all three across the river ?

What must the farmer take across ?
(The chicken; because it cannot be left with either of the other two)

What must the farmer take across second ?
(either the fox or the corn)

Math Problem - Infinite Square

2009-12-12T02:17:00.000-08:00

This question is from SIPENMARU (Admissions Selection) in 1987. If today is SNMPTN.

Problem:
Total area of this square is ....

A. 2a^2
B. 3a^2
C. 4a^2
D. 5a^2
E. Infinite

See the solution below !

Solution:
Look the square below:

Suppose that the area of square is L1 = a^2.
Then we have,
x = the root of (1/2 a^2) -- > Use Phytagoras Theorem

The area of second square = L2 = x^2 = 1/2 a^2.
Then,
L1 + L2 + L3 + ....= a^2 + 1/2 a ^2 + ....

You know that this equation above is Geometry Series, with Rasio (r)

r = 1/2 a ^2 / a^2 = 1/2

Finally we have,

S~ = a / 1 - r = a ^2 / 1- 1/2 = 2a^2.

So the answer is A. 2a^2.

Probability Problem Part 1

2009-12-02T23:33:00.000-08:00

After, we discuss about arithmetic, it's time to solve the probability problem. I have one problem about it.

Problem:
There is a family in small village, and they are consist of one father, one mother and 2 children. At one point they want to sit side by side in front of the house. The probability that father and mother sit next to each other is ...

How to solve this problem ? Let's discuss it !!!
Answer:

Supposed that:
His father (A), his Mother (B), Child 1 (C), Child 2 (D)
This problem is part of permutation. We know that permutation is, because the sequence is important.

And we know that ABCD and BACD is a different thing.
We know that,
n (S) = 4P4 = 24.

Mother's father side by side, consider the formation of 3 people sitting: 3P3 = 6 ways. Mother's father sitting position = 2P2 = 2. So the number of possibilities: 6 × 2 = 12 ways.

P (mother's father side) = 12/24 = 1 / 2

Manually:
ABCD BACD
ABDC BADC
CABD CBAD
DABC DBAC
CDAB CDBA
DCAB DCBA

The Answer Of My Previous Post (Maximum Triangles)

2009-12-02T22:46:00.000-08:00

In my previous post, we have a problem like this.

How many triangles could be formed ? Let's check it out.

First, we can find, the area of the big triange which side is 3 cm,

L1 = 1/2 * 3 * 3 * sin 60 = 9/4

And L2 = 1/2 * 1 * 1 * sin 60 = 1/4

Because L1 = n L2, we can conclude that,

n (the number of triangles formed) = L1/L2 = 9/4 / 1/4 = 9.

So, the number of triangles are 9.

Do you know the answer ?

2009-12-01T03:25:00.000-08:00

For anyone who knows the answer, please be informed.

The length of the equilateral triangle is 3 cm and each side made triangle reply sides 1 cm long. How many maximum small triangle can be formed ?

Math For Grade 6 Part 2

2009-11-30T15:46:00.000-08:00

Problem 1:

These were the scores of pupils in a class who took a mathematics test which had a maximum score of 50 marks.

3 pupils: 48 marks,    1 pupil: 26 marks, 2 pupils: 47 marks, 1 pupil: 45 marks,
4 pupils: 44 marks,    5 pupils: 43 marks, 1 pupil: 27 marks, 2 pupils: 29 marks,
1 pupil: 30 marks,    2 pupils: 32 marks, 2 pupils: 35 marks, 2 pupils: 38 marks,
1 pupil: 40 marks,    3 pupils: 41 marks

In your exercise book: a)   write the data in a table    b) draw a bar chart.
c)    What is:     i) the range       ii) the mode     iii) the mean of the data?

Problem 2:
In a survey about television programmes, a quarter of the people questioned preferred nature programmes, an eighth preferred science programmes, 3 eighths preferred   romantic films, an eighth preferred sports events and 40 people preferred game shows.
   a)    Draw a pie chart to show the data.
   b)    What part of the number of people questioned preferred game shows ?
   c)    How many people were questioned in the survey ?
   d)    How many people preferred each of the first 4 types of programmes ?

Problem 3:
The school bus is always late in the morning. James was so fed up that he noted the number of minutes it was late every day for a week so that he could write a letter of complaint to the bus company. The bus is due at James' bus stop at 8.24 am and these were the times it arrived.
Mon: 8.43 am, Tue: 8.29 am, Wed: 8.25 am, Thu: 8.50 am, Fri: 8.36 am
In your exercise book:
   a)    list the number of minutes the bus was late each day in increasing order;
   b)    calculate the range, median and mean of the data;
   c)    write a letter of complaint using these values

Problem 4:
Alice and Ben are discussing a problem about which is the better buy. One shop reduces the original price of an item costing £100 by 0.3. Another shop cuts 2 tenths off the original price of £100, then cuts 0.1 off the reduced price. Alice thinks that the first shop has the better offer. Ben thinks that they are the same.

Who do you agree with ? Why ? Write a sentence in your exercise book.

Problem 5:
Solve the problems in your exercise book.
a) The original price of an item was reduced by 0.14 and it now costs £192. What was its original price ?

b) A shop reduced the £60 price of a pair of shoes by 1 fifth, then later increased the reduced price by 1 quarter. How much do the shoes cost now?

Problem 6:
Write a plan, do the calculation and write the answer in a sentence. Three pieces of wood were cut from a 6.5 m plank. The 1st piece was 3 fifths of a metre, the 2nd piece was 4 fifths of a metre and the 3rd piece was 3 times the length of the 1st piece. What length of plank was cut off altogether? What length was left ?

Problem 7:
Solve the problems in your exercise book.
a)   Five metres of material cost £4.50. How much does 1 metre cost ?
b)   A car travelled 174 miles in 3 hours. How far did it travel in 1 hour ?
c)   A bee flies 30 metres in half a minute. How far does it fly in 1 minute ?
d)   What is the price of 1 kg of fruit if 1 quarter of a kg costs £2 ?
e)   I bought 3 fifths of a kg of beef for £6. What was the price per kilogram ?

Problem 8:
Write different plans for each problem. Use one of them to solve the problem.
a) In a class there are 15 girls, which is 6 tenths of the number of boys. How many pupils are in the class ?

b) If 150 km is 2 thirds of a journey, what is the length of the whole journey ?

Math For Grade 6 Part 1

2009-11-30T15:34:00.000-08:00

Problem 1:

Write a plan, do the calculation and write the answer in your exercise book.
a) Yesterday I bought 3 quarters of a kg of potatoes and today I bought half a kg of potatoes. How many kg of potatoes did I buy altogether ?

b) A family took 3 quarters of a kg of grapes on a picnic. How many kg of grapes did they bring home if they ate 3 fifths of a kg during the picnic ?

c) Two friends decide to walk to the beach, which is 2 and 3 quarter kilometres from their camp site. They walk 1 and 5 sixths kilometres, then have a rest. How far do they still have to go?

Problem 2:
I had lots of Christmas cards to write. I wrote 1 third on Monday, 2 eighths on Tuesday, 1 sixth on Wednesday and wrote the remaining 27 cards on Thursday.
How many Christmas cards did I send ?

Problem 3:
Solve the problems in your exercise book.

a) The road sign shows that it is 15 1/2 miles to Stanstead Airport. If our coach is travelling at a speed of 96 km per hour, how long will it be before we get there ?

b)   What is 2 thirds of 360 lb in kg ?

c) A capacity of 1 litre is practically equivalent to 1000 cm³, and 1 kg of water is close to 1 litre. How many kg is 600 cm3 of water ?

Problem 4:
a) What is your mass: i)     in grams    ii) in tonnes ? (Answer to the nearest kg.)

b) The weight of any object on the moon would be 1 sixth lighter than it is here on Earth. What would the mass of a 1 kg loaf of bread be on the Moon ?

c) A plane took off at 8.45 am in Budapest and landed at 12.35 pm in New York. If New York time is 6 hours earlier than Budapest time, how long was the flight?

Problem 5:
a) A plane left London at 11.00 am on Saturday for an 11 hour flight to San Francisco. What was the time in San Francisco when it landed ?

b) A plane left London for Moscow at 10.00 pm on Sunday. It was 4.00 am on Monday in Moscow when it landed. How long was the flight ?

c) A plane landed at 12 noon in London after a 9 and a half hour flight from Beijing. What time was it in Beijing when the plane took off ?

Math Exercise For Grade 6

2009-11-30T05:55:00.000-08:00

Part 1:

Solve these problems in your exercise book.
a) A group of 6 people met a group of 11 people. Each member of the first group shook hands with each member of the second group. How many handshakes were there?
b) Lee measured his heartbeat as 72 beats in a minute. How many times did his
heart beat in 21 minutes ?
c) A butcher bought 57 kg of meat for £1026. How much did he pay per kg?
d) A spare part for a car costs £63. How many such parts can the garage buy for £2696 ?

Part 2:
If it is possible, solve the problem in your exercise book and write the answer here. Underline any data which are not needed. List any important data which are missing.

a) Peter is 16 years old but his savings are just one fifteenth of the savings of his sister who is 5 years younger than he is. How much has Peter saved if his sister has saved £7500 ?
................................................................

b) In London, 15 mm of rain fell at 3 am. At 1800 hours, there was another downpour. How much rain fell then ?
................................................................

c) Cindy is 5 years old and weighs 24 kg. Her grandfather is 13 times older. How old is Cindy's grandfather and how much does he weigh?

Part 3:

Solve the problems in your exercise book.
a) Tom was given £50 for his birthday. He treated 3 friends to the cinema an they all had an ice-cream. If a cinema ticket cost £7.25 and an ice-cream tub cost £1.30, how much money did Tom have left ?

b) Mary found 54 buttons in her Gran's sewing box. Gran said that she used to
have 15 times as many. How many buttons used to be in the sewing box ?

c) Mum made 6 lbs of marmelade with 852 g of Seville oranges and 2.7 kg of sugar. What ingredients would she need to make 16 lbs of marmelade ?

Part 4:
Solve these problems in your exercise book.
a) A natural number ends in zero. If we leave off the zero we get another number. The sum of these two numbers is 5445. What was the original number ?
b) The difference between a number ending in zero and a second number, formed by leaving off the zero of the first number, is 5445. What was the first number?

c) Is it possible that the product of two consecutive natural numbers ends in:
i) 4 ii) 8 iii) 6 ?
d) Calculate the sum of the digits in the number 38 516 then subtract it from 38 516. Is the difference divisible by 9 ? Try it with other natural numbers.

e) I thought of a 5-digit natural number. When I wrote a '4' in front of it, the 6-digit number I made was 4 times as much as the number I would have made if I had written the 4 at the end of the 5-digit number. What was the number that I first thought of ?

Arithmetic For High School Students

2009-11-29T15:53:00.001-08:00

Here's a math problem that you can learn to prepare for your exams.
1. The number of first n rows of arithmetic interest are Sn =- n2 + 4n.
General formula tribe the nth row is the arithmetic ....
A. Un =-2n + 5
B. Un =-2n +4
C. Un =-2n + 3
D. Un = -2n -5
E. Un = -2n - 6

2. An arithmetic sequence, the third tribe is 36, the amount of interest is the fifth and seventh 144. Number ten tribes is the first series ....
A. 840
B. 660
C. 640
D. 630
E. 315

3. One mother shared a candy to children under 5 rows arithmetic rules. The younger the age of children more and more candy obtained. If a lot of candy the child receives the 11 fruits and 19 fruits fourth child, then the total number of candy .... fruit.
A. 60
B. 65
C. 70
D. 75
E. 80

4. A child in a bank savings to the difference between the increase in permanent savings. In the first month of USD $ 50,000.00, the second month of the third month USD $ 55,000.00 USD 60,000.00 and so on. Big savings are children ....
A. USD 1,315,000.00
B. USD 1,320,000.00
C. USD 2,040,000.00
D. USD 2,580,000.00
E. USD 2,640,000.00

5. An arithmetic sequence is known U3 = U7 = 13 and 29. Number twenty-five tribes are the first series ....
A. 3,250
B. 2,650
C. 1,625
D. 1,325
E. 1,225

6. Number n first fruit of tribal arithmetic series is given by Sn = n / 2 (5n-19). The different series is ....
A. -5
B. -3
C. -2
D. 3
E. 5

7. Four positive numbers forming arithmetic. If the multiplication first and fourth numbers are 46, and multiplication second and third number is 144, then the fourth number is the number .....
A. 49
B. 50
C. 95
D. 95
E. 98

8. Arithmetic series of tribes known terngah 32. If the number n the tribe's first 672 series, many tribes are the series ....
A. 17
B. 19
C. 21
D. 23
E. 25

9. Three positive numbers forming the geometry of numbers. If the three numbers are added to the result 7 / 4 and if multiplied result 1 / 8. The third largest number of these numbers is ....
A. 2
B. 1
C. 1 / 2
D. 1 / 3
E. 1 / 8

10. A car purchased at a price of USD $ 80,000,000.00. Each year the value of selling into 3 / 4 of the previous price. How selling value after 3 years of use .....
A. USD 20,000,000.00
B. USD $ 25. 312.500,00
C. USD 33,750,000.00
D. USD 35,000,000.00
E. USD 45,000,000.00

11. A ball falls from a height of 10 meters and bounce back with a height of 3 / 4 times the previous high, and so on until the ball stops. The total number of trajectory the ball is ....
A. 65 m
B. 70 m
C. 75 m
D. 77 m
E. 80 m

12. A rope was cut into 7 pieces and each piece forming a long line of geometry. If the length of the shortest piece of rope equal to 6 cm and the longest piece of rope equal to 384 cm, overall length of the rope is .... cm
A. 378
B. 390
C. 570
D. 762
E. 1,530

13. The number of infinite geometric series is the root of 2 + 1 + 1 / 2 root 2 + 1 / 2 + .... is ....
A. 2 / 3 (root 2 + 1)
B. 3 / 2 (root 2 + 1)
C. 2 (root 2 + 1)
D. 3 (root 2 + 1)
E. 4 (root 2 + 1)

14. The number of infinite geometric series is 7, while the number of tribes that are even-numbered 3. The first term runs it is ....
A. 7 / 4
B. 3 / 4
C. 4 / 7
D. 1 / 2
E. 1 / 4

15. The population of a city every year to follow the rules of the line geometry. In the year 1996 as many as the growth 6 people, the year 1998 as many as 54 people. Population in 2001 is ..... peoples.
A. 324
B. 486
C. 648
D. 1,458
E. 4,374

Math Games

2009-11-29T05:27:00.001-08:00

Part 1

An alphametic is a sum in which all of the digits have been replaced by letters (each letter always representing the same digit, and each different digit always represented by the same letter) and with the resulting arrangement forming real words.

After solving this alphametic

S A V E + M O R E = M O N E Y
give the value of SOME.

Part 2

Carter fenced in a rectangular plot of land and then divided it into two halves by putting another fence along the main diagonal. This diagonal fence measured 41 metres exactly. Martindale also fenced in a rectangular plot of land in a similar way (including the diagonal fence) but his rectangle was one-third greater in area than Carter's plot and used less fencing. In both plots all the the dimensions (lengths, widths and diagonals) were a whole number of metres.

How much more fencing did Carter use than Martindale?

Math Puzzle For Students

2009-11-29T05:23:00.000-08:00

Part 1
Mr Kitto was exactly 5 years older than his wife and they had two children, who were twins and went to the local comprehensive school.
One evening, one of the twins (who had just been given a calculator) announced that if you multiplied together the parents' ages, and then added together the twins' ages, and divided one result by another, the answer was 57 exactly.
How old was Mr Kitto?

Part 2
At a recent athletics meeting, five old acquaintances: Fred, Greta, Hans, Iolo and Jan met together for the first time since leaving college, so they had a lot of news to catch up on.

It seemed they all lived in different towns: Acton, Buswick, Coalford, Derby and Eccles; and that they all had different jobs which were, in no particular order: an engineer, a lawyer, a teacher, a doctor and a shopkeeper.
To round it off, each one was the winner in just one event at the meeting. These were: 100 metres, 400 metres, 1500 metres, High Jump and Javelin.
The following facts were also known:
1. Hans the shopkeeper from Derby won the High Jump.
2. The lawyer was from Eccles and said he was not a runner.
3. Greta was P.E. teacher from Buswick and won the 1500 metres
4. The doctor, who came from Acton, did not win the 100 metres.
5. The person from Derby was not an engineer.
6. Iolo was an engineer from Coalford and did not win the 400 metres.
7. Jan was not a lawyer, but did win the the 400 metres.
8. Fred did not come from Acton and was not a runner.(a) Which event did the person from Coalford win?
(b) Which town did Jan come from?
(c) What was the name of the lawyer?
(d) Which event did the engineer win?
(e) Which event did Fred win?

Mind-Reading Number Trick

2009-11-29T01:34:00.001-08:00

Think of a number, any positive integer (but keep it small so you can do computations in your head).
1. Square it.
2. Add the result to your original number.
3. Divide by your original number.
4. Add, oh I don't know, say 17.
5. Subtract your original number.
6. Divide by 6.
The number you are thinking of now is 3 !

Multiplication Tricks

2009-11-29T01:33:00.002-08:00

Multiply by 11
The eleven times table has always been very easy to learn up to 9 x 11. Here's a simple way of multiplying large numbers by 11 too. Let's try. Write down the first digit.

Add the first and second digits. Write it.
Add the second and third digits. Write it.
Again and again do this.
Write down the last digit.
Example 1 - 425 x 11
First number = 4
4 + 2 = 6. 2 + 5 = 7
Last number = 5
The answer is 4675.
Example 2 - 5890 x 11
First number = 5.
5 + 8 = 13. Now we can't write 13. So, add 1 into 5. Then write down 3.
8 + 9 = 17. Again add 1 into 3. Now it is 4. After that write down 7.
9 + 0 = 9. Then write down last digit. It is 0.
Answer : 64790

Finger Math: 9X Rule

2009-11-29T01:33:00.000-08:00

To multiply by 9,try this:
(1) Spread your two hands out and place them on a desk or table in front of you.
(2) To multiply by 3, fold down the 3rd finger from the left. To multiply by 4, it would be the 4th finger and so on.
(3) the answer is 27 ... READ it from the two fingers on the left of the folded down finger and the 7 fingers on the right of it.

This works for anything up to 9x10 !

The 11 Rule

2009-11-29T01:31:00.001-08:00

You likely all know the 10 rule (to multiply by 10, just add a 0 behind the number) but do you know the 11 rule? It is as easy! You should be able to do this one in you head for any two digit number. Practice it on paper first! To multiply any two digit number by 11:
For this example we will use 54.
Separate the two digits in you mind (5__4).
Notice the hole between them!
Add the 5 and the 4 together (5+4=9)
Put the resulting 9 in the hole 594. That's it! 11 x 54=594
The only thing tricky to remember is that if the result of the addition is greater than 9, you only put the "ones" digit in the hole and carry the "tens" digit from the addition. For example 11 x 57 ... 5__7 ... 5+7=12 ... put the 2 in the hole and add the 1 from the 12 to the 5 in to get 6 for a result of 627 ... 11 x 57 = 627

Practice it on paper first!

Sex Math Trick

2009-11-29T01:30:00.000-08:00

Your Age by Sex Math. This is pretty neat! Check it out....

YOUR AGE BY SEX MATH
DON'T CHEAT BY SCROLLING DOWN FIRST!

It takes less than a minute....... Work this out as you read... You might need a small piece of scrap paper for simple addition and subtraction.

1. First of all, pick the number of times a week that you would like to have sex. (more than once but less than 10)
2. Multiply this number by 2 (Just to be bold)
3. Add 5. (for Sunday)
4. Multiply it by 50 I'll wait while you get the calculator................
5. If you have already had your birthday this year add 1755.... If you haven't, add 1754 ....
6. Now subtract the four digit year that you were born.

You should have a three digit number. The first digit of this was your original number (i.e., how many times you want to have sex each week). The next two numbers are .........
YOUR AGE! (Oh YES, it is!!!!!)

5 squared shortcut Trick 2

2009-11-29T01:26:00.001-08:00

This works for any number ending in but when the numbers get over 100 it tends to get a little trickier with the multiplication. Give it a try with another number.
Try , it isn't difficult. Split the numbers apart:
8 and
Again, forget about the
Add 1 to 8
8 + 1 = 9
Multiply 9 by the first number, which was 8
9 X 8 =72
Now, put all the numbers together, 72 and
= 25

5 squared shortcut Trick 1

2009-11-29T01:24:00.001-08:00

Here is a really quick way to square any number with a 5 on the end Lets take

Ok, so what you have to do is split up the numbers, giving you and Forget about the for the moment and do this:
Always add 1, adding 1 to the 4, so we get 4 + 1 = 5
Then multiply this answer, 5, by the original first number, 4
5 X 4 = 20
So what you have is 20 and
Everyone knows = 25 right? Well it does. This is what makes it easy.
Put the two answers together and that's the answer !
2025

Joker’s Math Trick 2

2009-11-29T01:22:00.001-08:00

Take the first 2 digits of your home phone number and add them to the last 2 digits of your phone number.
Multiply by 365.
Write the number on a new sheet of paper.
Fold the first page in half.
Now fold the second page.
Place them side by side.
Now pick up the two sheets - sheet one in your left hand and sheet two in your right hand.
Find a bin/drawer and place the sheets in it.

Now using both your hands...
Slap yourself around the head while repeating:
"I'm a stupid person who wastes too much time on junk like this."

Joker’s Math Trick 1

2009-11-29T01:21:00.000-08:00

Complete this amazing Math Trick just follow the instruction below and complete the steps. You'll be surprised with the results ! All you'll need is a pen or pencil and some paper!

Pick a number between 1 and 100.
Multiply it by 5.
Add your age minus the number in family.
Divide the number by 10 rounding to the nearest decimal.
Write down the number on one side of a piece of paper.
Pick another different number between 1 and 100. .
Multiply by 1998.
Add the number in your family and subtract your age.
Divide the number by 10 rounding to the nearest decimal.
Write down the number on the other side of the piece of paper.

Phone Number Trick

2009-11-29T01:16:00.000-08:00

Here is a math trick so unbelievable that it will stump you. Personally Iwould like to know who came up with this and why that person is not running the country.

1. Grab a calculator. (you won't be able to do this one in your head)
2. Key in the first three digits of your phone number (NOT the area code)
3. Multiply by 80
4. Add 1
5. Multiply by 250
6. Add the last 4 digits of your phone number
7. Add the last 4 digits of your phone number again.
8. Subtract 250
9. Divide number by 2
Do you recognize the answer ??????

THE AMAZING MATH TRICK OF 1999

2009-11-29T01:14:00.000-08:00

Math Trick Of 1999:
1. First of all, pick the number of days a week that you would like to eat out.
2. Multiply this number by 2.
3. Add 5.
4. Multiply it by 50.
5. If you have already had your birthday this year . . . add 1749. If you have NOT had your birthday yet this year . . . add 1748.
6. Last step: Subtract the four digit year that you were born.

You should now have a three digit number:
The first digit of this was your original number (i.e.
how many times you want to go out to eat each week).

The second two digits are your age !!!
This is the only year it will ever work, so spread the
fun around while it lasts . . .

The Prime Number Trick

2009-11-29T01:11:00.001-08:00

Using prime numbers, you can amaze your friends with a prime prediction...
Ask your friends to pick any prime number bigger than 5, but they must not tell you what it is. Square it. (In other words multiply the prime number by itself.)
Add 17
Divide by 12

Without knowing which prime number your friends picked, you can still tell them:

There will be a remainder of 6.

For example, if you want to try the trick with the prime number 2801, here's what to push:
2801 * 2801 =
+ 17 =
/ 12 =
...and that's the answer ! Now find a new prime number and try it.

The "24" Mystery!

2009-11-29T01:09:00.001-08:00

A Murderous Math fan called OBAID pointed out that if you square ANY prime number bigger then 3, then subtract 1, the answer always divides by 24! E.g. 112 = 121 then 121 - 1 = 120 and yes 120 does divide by 24.

WHY ?
If you understand algebra, (and you've read The Phantom X ) then you'll know that all prime numbers can be written as (6n+1) or (6n-1).
(6n+1)2 = 36n+12n+1. So (6n+1)2 -1 = 36n+12n. This factories to 12n(3n+1). Either n or (3n+1) must be even, therefore the whole expression must be divisible by 24.
(6n-1)2 = 36n-12n+1. So (6n-1)2 -1 = 36n-12n. This factories to 12n(3n-1). Either n or (3n-1) must be even, therefore the whole expression must be divisible by 24.

Birthday Trick

2009-11-29T01:07:00.001-08:00

This math trick will determine your birthday. Just follow the steps with a calculator and press equal after each step. Go ahead and try the trick without cheating! For a simple, online JavaScript calculator, click on the calculator button.

   1. Add 18 to your birth month
   2. Multiply by 25
   3. Subtract 333
   4. Multiply by 8
   5. Subtract 554
   6. Divide by 2
   7. Add your birth date
   8. Multiply by 5
   9. Add 692
10. Multiply by 20
11. Add only the last two digits of your birth year
12. Subtract 32940 to get your birthday!

The answer's format is: month/day/year. For example, an answer of 123199 means that you were born on December 31, 1999. If the answer is not right, you followed the directions incorrectly or lied about your birthday.

Amazing Math Trick - Part 3

2009-11-29T01:05:00.000-08:00

The MISSING DIGIT trick !

Here it is!
Go and hide in a cupboard, or cover your eyes in some way so that you can't see what your friend is writing.

Ask a friend to secretly write down ANY number (at least four digits long).

e.g. 78341
Ask the friend to add up the digits... e.g. 7+8+3+4+1 = 23
... and then subtract the answer from the first number. e.g. 78341 - 23 = 78318
Your friend then crosses out ONE digit from the answer. (It can be any digit except a zero)
e.g. 7x318
Your friend then reads out what digits are left .e.g. 7-3-1-8
Even though you haven't seen any numbers, you can say what the missing digit is ! EIGHT

THE SECRET
This great trick relies on the power of 9.
After your friend has added up the digits and subtracted them, the answer will ALWAYS divide by 9. If a number divides by nine, then when you add the digits up, they will also divide by 9. If you check our example 7+8+3+1+8 = 27 which does divide by nine.
When your friend crosses a digit out, he then reads out the digits that are left. You add them up. In the example we had 7+3+1+8 = 19
All you do now is see what you have to add on to your answer to get the next number that divides by nine! The next number to divide by 9 after 19 is 27. So you need to add on EIGHT. This is the number that was crossed out!

Amazing Math Trick - Part 2

2009-11-29T01:02:00.000-08:00

The 3367 trick:

This trick is similar to the 7-11-13 trick. It's harder to do, but it looks far more miraculous ! Get a friend to pick any 2 digit number e.g. 74
x 3367
To work out the final answer you have to imagine the original number written out three times e.g. 747474 then divide it by three.

249158
This one takes practice, but unlike the others, it's very hard to see how it's done!

Amazing Math Trick - Part 1

2009-11-29T01:01:00.000-08:00

The 7-11-13 trick!

This trick makes you look like your brain is a mega fast calculator! Ask a friend to write down ANY three digit number such as 231 or 884. Ask them to multiply the number by
x 7
x 11
x 13

... but even if your friend has used a calculator, you will have written down the answer ages ago! It's fiendish!

THE SECRET: all you do is write out the starting number twice! So 231 will become 231231 and 884 will become 884884. You don't believe it? Well try it on this calculator and see for yourself! You work this calculator by clicking the mouse on the buttons. Go on, put in ANY three digit number then x7 x11 x 13 and see what you get!

How to solve a math problem!

2009-11-28T23:41:00.000-08:00

Step 1:

Read the problem.

Step 2:

Find out, What am I supposed to find out ? If it’s too complicated to understand the 1st time… Read the problem again and AGAIN !

Step 3:

Look for clue words. To show you which operation to use, Addition, Substructin, Multiplication or Division. Beware… Of red herrings ! (false clues) In this case, numbers that are just there to trick you, but are not needed to solve the problem. If you’ve read the question more than once, and you still don’t know which way to turn.. Then just do something ! You know there are four operations and you’ll have to do at least one of them. So pick one. You know you need to do that operation using at least two numbers, so pick two of the numbers in the problem. Then either add ‘em, subtract ‘em, multiply ‘em, or divide em. You may be wrong, but YOU MAY BE RIGHT !

Step 4:

Solve the problem.

Step 5:
Now think… Does this answer make sense ? Would I expect this to be the answer ?

Step 6:
Ask yourself… Are there more parts to this question? (Some questions have two or more parts!) Remember, If you ONLY answer half the question, EVEN if you get that half 100% right… That’s only 50% of the question... And 50% is an F!

Step 7:
Check your work… just work backwards, using the opposite operations and see if you end up where you began. Congratulations, That’s how to solve a math problem. Some more clues for math sleuths… Always try something.Never try nothing. Show your work and hand it in. Even if you don’t make it the whole way, you may have come close.

Pictures Posting

2009-11-25T03:45:00.000-08:00

This post is to try to post pictures. You can see my smile ?

My First Posting

2009-11-25T03:38:00.000-08:00

This is my first post on this blog. This blog will contain all things related to math. I hope you can always visit this blog.