If n is a perfect square, √n is an integer. If n is a positive non-square, √n is irrational.

Steps

1. Recognize squares: 1, 4, 9, 16, 25, …
2. For √k² with k ≥ 0, the principal root is k.
3. If asked whether √n is rational and n is not a perfect square, answer irrational.