Shortcut to square any number from 90 to 99

Shortcut to square any number from 90 to 99 is one of my favorite that I like to apply when I see a number such as 98 or 99 as all I need to know is how to subtract and square of numbers from 1 to 9.

Now lets go through the steps

Step 1:Assume 100 as base and find the difference between the number to be squared and 100.

Step 2:Subtract the difference in step 1 from the number to be squared to find tenth place digit.

Step 3:Square the difference and place it next to step 2.

Once you know the technique you can square any number from 90 to 99 mentally.

Example 1: 98²=?
Step 1:Assuming 100 as base, we shall find the difference
100-98=2
We get the difference as 2

Step 2:Subtracting the difference(2) from the number to be squared(98) we get,
98-2=96
96 is the tenth place digit

Step 3:Squaring the difference we found in step 1 we get
2²=4
4 is the Unit place digit.
Ans 98²=9604

Example 2: 99²=?

Step 1:Assuming 100 as base, we shall find the difference between the number to be squared(99) and 100.
100-99=1
We get the difference as 1

Step 2:Subtracting the difference(2) from the number to be squared(98) we get,
99-1=98
98 is the tenth place digit

Step 3:Squaring the difference we found in step 1 we get
1²=1
1 is the Unit place digit.

Ans   99²=9801

Example 3: 97²=?

Step 1:Assuming 100 as base, we shall find the difference between the number to be squared(97) and 100.
100-97=3
We get the difference as 3

Step 2:Subtracting the difference(3) from the number to be squared(97) we get,
97-3=94
94 is the tenth place digit

Step 3:Squaring the difference we found in step 1 we get
3²=9
9 is the Unit place digit.

Ans   97²=9409