amazing math tips & tricks

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Welcome to the World of MATHEMA- TRICKS Minhas Kamal

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Page 1: Amazing Math Tips & Tricks

Welcome to the World of MATHEMA-TRICKS

Minhas Kamal

Page 2: Amazing Math Tips & Tricks

Today we will learn some cool math tricks.

So that, we can use more our brain and less our calculator.

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Page 3: Amazing Math Tips & Tricks

Square a two digit number ending in 5

For example: 152, 452, 852

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Page 4: Amazing Math Tips & Tricks

Square a two digit number ending in 5

Lets consider the number 35.1. We take the first digit and multiply it with it’s nextnumber.

3 5

3 * 4 = 12

2. Then simply put 25 after it.1 2 2 5

So, 352 = 12253

Page 5: Amazing Math Tips & Tricks

Square a two digit number ending in 5

Here is another example:Step-1:

9 5

9 * 10 = 90Setp-2:

9 0 2 5So, 952 = 9025

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Page 6: Amazing Math Tips & Tricks

Multiply any number by 4

Simply double the number two times.

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Page 7: Amazing Math Tips & Tricks

Multiply any number by 4

Take the number 6363*4 = 63*(2*2) = (63*2)*2 = 126*2 = 252

Lets try another number 753double of 753 = 1506double of 1506 = 3012So, 753 * 4 = 3012

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Page 8: Amazing Math Tips & Tricks

Multiply any number by 5

Simply half the number &multiply it by 10.

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Page 9: Amazing Math Tips & Tricks

Multiply any number by 5

Take the number 8686*5 = 86*(10/2) = (86/2)*10 = 43*10 = 430

Lets try another number 495half of 495 = 247.5247.5 * 10 = 2475So, 495 * 4 = 2475

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Page 10: Amazing Math Tips & Tricks

Multiply any number by 15

Multiplication by 10 + Multiplication by 5.

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Page 11: Amazing Math Tips & Tricks

Multiply any number by 15

Take the number 8484*10 = 84084*5 = (84/2)*10 = 42*10 = 42084*15 = 840 + 420 = 1260

Lets try another number 495495*15 = 495*10 + 495*5

= 4950 + (495/2) * 10 = 4950 + 2475 = 7425

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Page 12: Amazing Math Tips & Tricks

Multiply any number by 11

x y z

x y + z zx + yxyz * 11 =

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Page 13: Amazing Math Tips & Tricks

Multiply any number by 11

Take the number 263

Lets try another number 485

2 6 3

2 9 38263 * 11 =

4 8 5

5 3 53263 * 11 = 11

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Page 14: Amazing Math Tips & Tricks

Multiply two numbers between 10 and 20

For example: 15*17, 19*13

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Page 15: Amazing Math Tips & Tricks

Multiply two numbers between 10 and 20

Lets consider the number 12*14.1. Add the first number with the other number’ssecond digit.

1 2 + 1 4

1 6

2. Place a 0(zero) after it.1 6 1 6 0

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Page 16: Amazing Math Tips & Tricks

Multiply two numbers between 10 and 20

3. Multiply the second digits of the two numbers.1 4

* 1 2 8

4. Add this number with the step-2 result.1 6 0

+ 81 6 8

So, 12*14 = 16815

Page 17: Amazing Math Tips & Tricks

Multiply two numbers between 10 and 20

Here is another example: 17*13

Step-1: 17 + 3 = 20

Setp-2: 20 200

Step-3: 7 * 3 = 21

Step-4: 200 + 21 = 221

So, 17*13 = 22116

Page 18: Amazing Math Tips & Tricks

Divisibility Check

For example: is 7403 is divisible by 11 ?

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Page 19: Amazing Math Tips & Tricks

Divisibility Check (for 2, 3)

A number is divisible by 2 if its last digit is 0, 2, 4, 6 or 8. For example: 12, 5394, 993120.

A number is divisible by 3 if sum of its digits is divisible by 3. For example: 72 is divisible by 3 as 7+2=9 which is divisible by 3.Another example: 57381, 5+7+3+8+1=24; 24 is divisible by 3. So 57381 is also divisible by 3.

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Page 20: Amazing Math Tips & Tricks

Divisibility Check (for 5, 7)

A number is divisible by 5 if its last digit is 0 or 5. For example: 100, 3795, 698170.

For 7, separate & double the last digit of the number. Then subtract it from the rest. Take: 91.

91 9 1 9 - (1*2) 7

Now, if the number is 0 or divisible by 7, then the original number is also divisible by 7.

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Page 21: Amazing Math Tips & Tricks

Divisibility Check (for 7)

If the number is big then continue the process as many time as needed.

Lets take 3752.3752 375 – 2*2 371 37 – 1*2 35

Now, 35 is divisible by 7. So, 3752 is also divisible by 7.You may have gone even further,

35 3 - 5*2 -7 ; which is also divisible by 7.

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Page 22: Amazing Math Tips & Tricks

Divisibility Check (for 11)

For 11, add and subtract digits in an alternative pattern (like- 1st digit - 2nd digit + 3rd digit …).Take: 8525

8 - 5 + 2 - 5 = 0So, it is divisible by 11.

Take: 3927553 - 9 + 2 - 7 + 5 - 5 = -11

Also divisible by 11

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Page 23: Amazing Math Tips & Tricks

Divisibility Check (for 13)

For 13, add 4 times of the last digit to the rest of the number. Take: 351

351 35+1*4 39

It is divisible by 13.Lets try another: 754

754 75 + 4*4 75 + 16 91 9+1*4 13

So, you know.22

Page 24: Amazing Math Tips & Tricks

So we have leant a lot of math tricks today.

Practice to make them perfect for you.

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Page 25: Amazing Math Tips & Tricks

There is one math trick only for

YOU!24

Page 26: Amazing Math Tips & Tricks

Lets see if you can do it right!

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Page 27: Amazing Math Tips & Tricks

Add these numbers one after another-

1000 20

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Page 28: Amazing Math Tips & Tricks

Add these numbers one after another-

1000 201000 30

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Page 29: Amazing Math Tips & Tricks

Add these numbers one after another-

1000 201000 301000 40

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Page 30: Amazing Math Tips & Tricks

Add these numbers one after another-

1000 201000 301000 401000 10

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Page 31: Amazing Math Tips & Tricks

Add these numbers one after another-

1000 201000 301000 401000 105000 ???

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Page 32: Amazing Math Tips & Tricks

Add these numbers one after another-

1000 201000 301000 401000 105000 ???

If your answer is 5000, then you are among the most who mistook. The actual answer is 4100. Count again and see if you get it right this time.

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Page 33: Amazing Math Tips & Tricks

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