Find the Missing Number — Dinosaurs — Grade 1

Each row gives a child the start and the finish and asks for the move between: a group of a T. rex, a stegosaurus and a raptor, the number still there, and a blank for how many left. Finding the missing number means connecting subtraction to its inverse — what taken from the group lands on the result. It is real Grade 1 reasoning, and the pictured dinosaurs plus within-twenty numbers keep it checkable by counting, so a child can verify the missing part instead of taking it on trust.

Change-unknown subtraction is harder than plain take-away precisely because the answer is the move, not the result — and that extra reasoning is the Grade 1 point. Keeping the numbers within twenty lets a child meet that challenge with strategies they have, counting up from the dinosaurs that remain to the group they started with.

Children who like dinosaurs take to the puzzle of working backward, and it suits a child ready for a little more than plain take-away. When this feels easy, try find the missing number with easter, or find the missing number with kitchen tools. You can also browse every subtraction worksheet or the whole dinosaurs collection for grade 1 — each sheet prints cleanly in black and white or plays online for free.