How to play: The top of the sea is zero. Numbers above the waves count up: 1, 2, 3.
Numbers under the waves are negative numbers: −1, −2, −3, getting smaller the deeper you go.
Move the dolphin up and down to answer the question, then press Check.
Deep Dive is a free online learning game for ages 9+. Leap and dive past zero to learn negative numbers. No ads, no sign-up.