Find the Missing Number — Birds — Grade 1

Each row gives a child the start and the finish and asks for the move between: a group of robins, owls and a duck, 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 birds plus within-twenty numbers keep it checkable by counting, so a child can verify the missing part instead of taking it on trust.

Working a subtraction backward — from result to the part that left — is how a child first sees that the same three numbers can be arranged more than one way. It is the seed of fact families, a Grade 1 idea, and finding the missing part with within-twenty birds keeps that seed planted in counting the child can actually do.

Children who like birds 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 more birds, or find the missing number with desserts and sweets. You can also browse every subtraction worksheet or the whole birds collection for grade 1 — each sheet prints cleanly in black and white or plays online for free.