I have come across questions requiring me to do the square root of 225 and the solve 2^9. Although I can do this by hand, it would take up valuable time. Are we expected to know these values like we do our basic multiplications? Are there tricks to solving roots and powers?
Well you should know squares of all number till 15 at least
and memorizing exponents of 2 till 10 is not a bad idea either.
But whenever there is a large number given on GMAT, there is probably a pattern that you could identify to solve the problem easily. And 225 is not at all a large number.
Hope this helps.

















