If you are looking for √16, you are looking for the square root of 16. The square root of a number is defined by what number multiplied by itself will get you. x^2 (a number squared) = 16. √16 = x. Let's try from numbers 1-5 for a square. 1x1 = 1 2x2 = 4 3x3 = 9 4x4 = 16 √16 = 4. I hope this helps!