Q: Find the largest number less than 4000 that is the square of an integer.
Explanation: The simplest, fastest way to do this is:
On a calculator, find the square root of 4000. It is 63.245…. Round this down to 63. Now, square 63. It is 3,969.
This is the way you should be thinking for SAT problems. If you decide instead to count down from 3,999, finding the square root of each number until you find a whole number, you will have to do this 31 times until you find the right one! (And by the way, why 31? Doesn’t 3999 – 3969 equal 30? Was I wrong? No! This is another little SAT trick. Always add 1 to include the first or last number, whichever one wasn’t counted in the original 30.)