5 Maths Tricks

Maths Tricks For Kids

Mathematics tricks are a must for every one. They save crucial time and helps us in faster calculation and more. Browse below to get Maths Tricks with answers to become a better Mathematician.

Math Trick #1:

How to multiply a two digit number by 11:

For example, 43×11. Take the original number and imagine a space between the two digits:

4_3
Now add the two numbers together and put them in the middle:
4_(4+3)_3 which is the same as 4_7_3
The answer… 473

If the numbers in the middle add up to a two digit number, insert the second number and add 1 to the first:

For example, 67×11

6_(6+7)_7
(6+1)_3_7 which is the same as 7_3_7
The answer… 737

Math Trick #2:

How to multiply big numbers by 5

Take any number, and then divide it by 2. Then…
If the result is whole(that is, there's no remainder), add a 0 at the end.
If it is not whole, ignore the remainder and add a 5at the end of the number.

For example, 4252×5 = (4252/2) and add a 5 or 0 to the end of the number

4252/2 = 2126 (it’s a whole number so add a 0 to the end)
The answer is 21260

Here’s another example: 8667×5

Divide the number by two: 4333.5 (there’s a remainder so add 5 to the end)
The answer is43335

Math Trick #3:

How to multiply by 9, or 99, or 999

Multiplying by 9 is really like multiplying by 10-1.

9×9 is the same as 9x(10-1) which is (9×10)-9 which is 90-9 or 81.
Let’s try a harder example: 56×9 = 56×10-56 = 560-56 = 504
To multiply by 99, it’s the same idea, except you multiply by 100-1.
So, 56×99 = 56x(100-1) = 5600-56 = 5544.
Multiplying by 999 is similar to multiplying by 9 and by 99, except now you multiply by 1000-1
22×999 = 22x(1000-1) = (22×1000) – (22×1) = 22000-22 = 21978

Math Trick #4:

How to square a two digit number ending in 5

If you need to square a two digit number ending in 5, multiply the first digit by itself + 1, and put 25 on the end.

For example, 65^2 (which can be written as 65×65)

6x(6+1) or 6×7 =42
Put a²⁵on the end of it.
The answer is 4225

Math Trick #5:

How to multiply by 4

The trick here is to simply multiply by two, then multiply by two again. Ultimately, you want to work with smaller numbers that are easier to work within your head.

For example 82 x 4 = (82 x 2) x 2 = (164) * 2 = 328

To multiply by 8, just multiply by 2 one more time (656).