Before you understand this shortcut method, you are advice to read:
What are Square Numbers ?
Observer the following table:
Table 1
| Natural Number | Square Number |
|---|
| 15 | 225 | | 25 | 625 | | 35 | 1225 | | 45 | 2025 |
Table one represents square of natural number having 5 at its one's place
You can observe that in square numbers:
Last two is always 25
Rest of the digits = [digit at ten's place X (1 + of digit at ten's place)]
Explaining the above observations with the help of following diagram again:
So now if you are asked to find square of 95 and 125, you can used the same technique and very quickly answer that:
95 = 9025
125 = 15625
(Elaboration of these again done in the following:)
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