To square 2-digit numbers having low digits:     ex. 31×31=961

-Square the ones digit of the 2-digit number being squared. This yields the ones digit of the answer (there may be a carry figure).    ex. 1×1=1 above

-Multiply the two digits of the 2-digit number together and double this figure, adding in any carry figure from above. This yields the tens digit of the answer (there may be a carry figure).    ex. 2(3×1)=6 above

-Square the tens digit of the 2-digit number being squared, adding in any carry figure from above. This yields the hundreds digit of the answer.    ex. 3×3=9 above

*note- This is a very easy and useful tool for squaring low digit numbers. Squaring higher digit numbers involves more effort due to having to hold in your head the carry figures (without forgetting them) while doing the next step. With practice you will find where other methods should be used instead.