This is a presentation on useful tips and tricks that can be used in mathematics. Please like and comment, it gives a lot of inspiration.

2. Introduction
In mathematics tricks are important to do
calculation faster and easier. In these slides
we will show you some tricks for fast and
easy calculation.

3. Multiplying by 4
This trick is very simple and yet logical. To multiply any
number by 4, just multiply it by 2 and then double the
answer. The basic concept of this trick is that you can
solve a multiplication problem by multiplying by its
factors. Let’s assume the number is 25.
Then:
25 x 4
25 x 2 = 50
50 x 2 = 100
25 x 4 = 100
This trick is based on a very simple fact:
2 x 2 = 4

4. Multiplication by 5
It's often more convenient instead of
multiplying by 5 to multiply first by 10 and
then divide by 2.
For example, 137×5 = 1370/2 = 685.

5. Multiplying by 12
12 X 7
The first thing is to always multiply the 1 of the twelve by
the
number we are multiplying by, in this case 7. So 1 X 7 =
7.
Multiply this 7 by 10 giving 70. (Why? We are working
with BASES here.)
Bases are the fundamentals to easy calculations for all
multiplication tables.
Now multiply the 7 by the 2 of twelve giving 14. Add this
to 70 giving 84.
Therefore 7 X 12 = 84

6. Multiplication of 2 Numbers
Step 1:
Let us consider multiplying any two digit numbers, for example 23 x 24.
Step 2:
Choose the unit digit of both the numerals and deduct it from the given numerals.
23 - 3 = 20
24 - 4 = 20
Step 3:
Now, select any one number (24) and add it with unit digit of another number(3)
24 + 3 = 27
Step 4:
Then, multiply the result obtained in step 2 and step 3.
27 x 20 = 540
Step 5:
Multiply the unit digit values.
4 x 3 = 12
Step 6:
Finally, add values obtained from step 3 and step 4.
540 + 12 = 552
23 x 24 = 552

7. Multiplication of 3 Numbers
Step 1:
Let us consider multiplication of three digit numbers 208 x 206.
Step 2:
Now, deduct the last digit from the respective numerals.
208 - 8 = 200
206 - 6 = 200
Step 3:
Pick any one number and add it with the unit digit of another number.
208 + 6 = 214
Step 4:
Now, multiply the result obtained in step 1 and step 2.
214 * 200 = 42800
Step 5:
Then, multiply the unit digits of the given numbers.
8 * 6 = 48
Step 6:
Add the values obtained in step 4 and step 5.
42800 + 48 = 42848
208 x 206 = 42848

8. To check divisibility of a number
2- A number is divisible by 2 if it is even.
3- A number is divisible by 3 if the sum of the digits is a multiple of 3.
Eg.)12-1+2=3
4-A number is divisible to 4 if the last two digits of the number are
divisible by 4.
5-A number is divisible by 5 if the last digit is 5 or 0.
6-A number is divisible by 6 if the number is divisible by 2 and 3.
7-A number is divisible by 7 if you double the last digit and subtract it
from the rest of the number and the answer is: 0, or
divisible by 7.
8-The last three digits are divisible by 8.
9-The sum of the digits is divisible by 9.
10-The number ends in 0.
11-If you sum every second digit and then subtract all other digits and the
answer is:0, or divisible by 11.
12-The number is divisible by both 3 and 4.

9. Squaring of numbers ending with 5
65x65=4225
Multiply the previous number 6 to one more
than itself 7. Then write 25.

10. Squaring two digit numbers
Say, you want a square of 13. Do this: add 3
(the last digit) to 13 (the number to be
squared) to get 16 = 13 + 3. Square the last
digit: 3² = 9. Append the result to the sum:
169.

11. Distributive Property
The Distributive Property is an algebra
property which is used to multiply a single
term and two or more terms inside a set of
parentheses.
Eg.) 103+101=100(3+1)