Why does the grandmother stay quiet?

She believes explaining too much would spoil his discovery (The text says she learned that explaining everything makes a child lose interest, so she lets silence work.)

What is the central idea of this passage?

Discovery means more when a person finds it themselves (The grandmother sees the boy teach himself 'the whole lesson,' showing self-discovery as the point.)

The word 'sidled' suggests the crab moved

sideways and cautiously ('Sidled' means to move sideways in a wary, careful way, matching the crab freezing with a lifted claw.)

What did the boy whisper after watching the crab?

"It's watching me back." (After leaning close for several minutes, the boy looks up with "his voice hushed with wonder" and whispers, "It's watching me back.")

The Tide Pool: Level 3 Reading Comprehension Questions

The boy crouched at the edge of the tide pool, holding his breath as if his breathing might scare the water. A small crab sidled out from under a rock, lifted one claw, and froze. His grandmother stood behind him, saying nothing. She had learned long ago that the surest way to make a child lose interest in a thing was to explain it to death. So she folded her hands and let the silence do its slow work.

The boy leaned closer, then closer still, until his nose nearly touched the surface. A minute passed, then two. After a while he looked up, his eyes wide and his voice hushed with wonder, and whispered, "It's watching me back." His grandmother nodded slowly.

That, she thought, was the whole lesson, and he had managed to teach it to himself without a single word from her. She would remember this small triumph longer than he would. The waves came in then, sliding up over the rocks and filling the pool to its brim, and the crab folded its claw and slipped quietly away into the deeper green.

Comprehension questions