* Whiteboard required
** This activity is teacher paced
How to square any numbers in your head - fast mental math trick here: https://www.youtube.com/watch?v=GEuyDHMG0jY
There is barely any calculation needed to mentally find the square a number that ends in five. How fast? The square of 45 is 1225; The square of 85 is 7225; the square of 115 is 12125; the square of 1095 is 1188125....as fast as I can type them I answer them!
The trick is this to faster squaring....
Say we have 65 squared. Get the number that is not 5 ( that is 6) and multiply it by the next number after it (7). Then just write 25 on the end.
So 6 x 7 = 42, our answer is 4225. Really. Simple 'eh?