Square roots • square roots are the of perfect squares. • a square root of a number is one of its two equal factors. (remember • 4 · 4 = 16, so 4 is the of 16. 16 = 4 the symbol ,called a is used to show a number’s square root. examples: √4 = 2 because √9 = 3 because √16 = 4 because √25 = 5 because √100 = 10 × = × = × = × = × = find each square root. times itself gives you 81? (? · ? = 81) 81 196 49 225 121 16 4 36 64