[Math Tricks]*Calculation Tricks For Doing Fast Math Part-4

Mathematics is not only limited to learning from textbooks. There are different learning styles that make mathematics easier. Simple maths tricks help us for fast calculations and to improve our mathematical skills. For example, the multiplication tricks will help students to learn maths tables and fast multiplication.

The mathematical tricks are not only helpful for school going kids but also supports you to manage time in final exams as well as in the competitive exam and solve the maths questions with accuracy. The well-known fact is that our human brain is similar to a computer. It means our brain is like the hardware of a computer whereas our mind is like a Software.

Therefore, learning simple arithmetic tricks will help the students to gain their confidence and enhance problem-solving skills. With these learning skills, they can achieve a big success in their upcoming future.

8 Magic Math Tricks For Fast Calculations

Imagine how mathematics would be easy and interesting when you have the ability to calculate the problems in a matter of seconds using some tricks. There are different kinds of arithmetic operations like addition, subtraction, division, multiplication, squaring, roots, powers, logarithms, divisions, etc. Here are some of the best tricks, which will help students to perform arithmetic calculations easily.

1. Addition Tricks

With the help of basic principles of tens and unit places, the addition of two-digit numbers is performed by

Take 43 + 34
Split the second number into tens and unit places. 34 = 30 + 4
Finish the ten’s addition. 43 + 30 = 73
Finally, add the remaining unit place digit. 73 + 4 = 77.

2. Tricks for Subtraction

Here is an example that requires a lot of borrowing

Consider two numbers say 1000 and 676
Subtract 1 from both the numbers; we get 999 and 675
Then subtract 675 from 999, we get 324
So, 1000 – 676 = 324.

3. Quick Multiplication by Breaking Down Numbers

Let’s try the number 24 and 16
First split the number 24, which gives 4 x 6
Then multiply 6 with 16, we get 96
Finally multiply the number, 96 x 4 = 384
So, the multiplication of two numbers 24 x 16 that gives the solution 384.

4. Multiplied By 15

Consider the multiplication of two numbers say 56 and 15
Now add zero at the end of the first number, it becomes 560.
Divide that number by 2; we get 560/2 = 280
Add the resultant number with 560, so 560 + 280 = 840.
So the answer for 56 and 15 is 840.

5. Multiplication of Two-Digit Numbers

If anyone of the given numbers is an even number, then follow the steps to solve

Consider an example, 18 x 37
Here 18 is an even number, then divide the first number in half, so that 18/2 = 9
Then double the second number. 37 x 2 =74
Finally, multiply the resultant numbers. It becomes 74 x 9 = 666

6. Division Tricks (Divisibility Rules)

The numbers that can be evenly divided by certain numbers are:

If a number is an even number and ends in 0, 2, 4, 6 or 8, it is divided by 2.
A number is divisible by 3 if the sum of the digits is divisible by 3. Consider the number 12 = 1 + 3 and 3 is divisible by 3.
A number is divisible by 4 if the last two digits are divisible by 4. Example: 9312. Here the last two digits are 12, and 12 is divisible by 4.
If the last digit is 0 or 5, it is divisible by 5
If a number is divisible by 2 and 3, then it is divisible by 6, since 6 is the product of 2 and 3.
If the number is divisible by 8, the last three digits of the numbers are divisible by 8.
If a number is divisible by 9, the sum of the digits is divided by 9. Let us consider the example, 4518 = 4 + 5 + 1 + 8 = 18, which is divisible by 9.
If the final digit of the number is 0, it is divisible by 10.

7. Trick to Find Percentage

Let us take; we have to find the percentage of the number 5% of 475, follow the steps.

For the given number, move the decimal point over by one place. 475 becomes 47.5
Then divide the number 47.5 by 2, we get 23.75.
23.75 is the solution to the given problem.

8. Calculation of Squares that Ends with the Digit 5

Let’s consider the number 75 to find its square.
Start writing the answer of last two digits number that is 25 because any number that ends with 5 is 25
Take the first digit of the number 75. That is 7 and take the number that follows 7 is 8.
Now, multiply 7 and 8, we get the number 56.
Finally, write the number 56 in the prefix and combine with 25 what we already wrote.
So, the answer is 5625.
Squares Ending in 5: n5 = n(n + 1)52 = n(n + 1)25 , where n is the first digit.
Example: Let’s consider the number 75 to find its square. Here n = 7,

So, 75 = 7(7 + 1)25 = (7 x 8) 25 = 5625.

Simple Math Tricks

Here are a few more maths tricks which are simple to remember.

Multiplication by 2 and 4: When a number is multiplied by 2 or 4, then the last digit of the resulting value will be an even number always.

Examples:

19 x 2 = 38

19 x 4 = 76

Multiplication by 5: When a number is multiplied by 5, then the resulting value will either end with 0 or 5. Examples:

11 x 5 = 55

8 x 5 = 40

121 x 5 = 605

Multiplication by 10: When a number is multiplied by 10, then the resulting value ends with 0 always.

Examples:

5 x 10 = 50

10 x 10 = 100

11 x 10 = 110

17 x 10 = 170

211 x 10 = 2110

Memorising Table of 9: It is easy to remember the table of 9. Just we need to focus on the pattern.

09, 18, 27, 36, 45, 54, 63, 72, 81, 90

We can see the numbers at the ten’s place are increasing by 1, and the numbers at the unit place are decreasing by 1.

Maths Tricks Questions

Find more maths tricks questions for practice here.

A merchant can place 8 large boxes or 10 small boxes into a carton for shipping. In one shipment, he sent a total of 96 boxes. If there are more large boxes than small boxes, how many cartons did he ship?
(A) 11 (B) 10 (C) 12 (D) 15 (E) 17
339% of 803 + 77.8% of 1107 = ?
(A) 3175 (B) 3320 (C) 3580 (D) 3710 (E) 3950
78.54 ÷ 0.03 + 22.8 ÷ 0.8 – 1470 × 1.25 = ?
(A) 809 (B) 807.5 (C) 805 (D) 802.5 (E) 801
The cost of 8 dozen eggs is Rs. 256. Which calculation is needed to find the cost of 9 eggs?
(A) (9 × 256) × (8 ÷ 12)
(B) (12 × 256) ÷ (8 × 9)
(C) (8 × 256) ÷ (9 × 12)
(D) (9 × 256) × (8 × 12)
(E) (9 × 256) ÷ (8 × 12)

For more math tips and tricks, to solve the complicated sum in a matter of seconds, register with BYJU’S – The Learning App and watch the interactive videos.

Frequently Asked Questions – FAQs

What is the use of maths tricks?

Maths tricks help us to do the calculation fast. It saves time and increases the chances of scoring more marks in the exams.

What are multiplication tricks?

The multiplication tricks are used to solve multiplication problems quickly and accurately. If we are able to memorize multiplication tables, then we can easily solve the questions based on them.

How to add in a faster way?

To add any two numbers in a faster way, follow the below steps:
Firstly, round up both the numbers by adding or subtracting small numbers.
Add the numbers.
Now subtract or add those values to get the final result.
For example, Add 799 and 299.
Round up 799 to 799+1 = 800 and 299 to 299+1 = 300
800+300 = 1100
Now subtract the added numbers from 1100,
1100-1-1 = 1100-2 = 1099

How to multiply quickly?

We can split the numbers and then multiply them. For example, multiply 81 and 24.
Splitting the number 81 = 8 x 9
Multiply 24 by 8, 24 x 8 = 192
Now multiply 192 x 9 = 1728
Hence, the multiplication of numbers by one digit number is easier.

How to find if a number is divisible by 9?

If a number is divisible by 9, the sum of the digits is divided by 9. Let us consider the example, 1728 = 1+ 7+2+8=18, which is divisible by 9.

How to find if a number is divisible by 13?

If a number N is given, then multiply the last digit of N with 4 and add it to the rest truncate of the number. If the outcome is divisible by 13, then the number N is also divisible by 13.
For example, 650 is divisible by 13 because;
65+0*4=65
65 is divisible by 13