Educational worksheet for classifying numbers as rational or irrational, aligned with Common Core standard 8.NS.A.1.

1) 2
2) 3
3) 4
4) 3
5) 2
6) 3
7) 1
8) 2
9) 4
10) 4
11) 1
12) √20; because 20 is not a perfect square, so its square root cannot be expressed as a fraction of two integers.
13) √164; because 164 is a perfect square (12.806... is not an integer, wait, 164 is not a perfect square. Correction: none of these are rational? Wait, let's recheck. Actually, 164 is not a perfect square. 99 is not. 196 is 14^2, so √196 = 14, which is rational. So the rational number is √196. Because 196 is a perfect square, its square root is an integer, which is a rational number.
14) √2; because it cannot be expressed as a ratio of two integers and its decimal representation is non-terminating and non-repeating.