Students use a 99 chart to develop strategies for addition and subtraction.

Cross Number Puzzles— Addition and Subtraction

Students use logical reasoning to find missing numbers in a 3 × 3 grid.

Students control the jumps of a rabbit to investigate number properties.

Students add two-digit and three-digit numbers on an open number line.

Students pair numbers together so that each pair sums to a target value.

Students use ten frames to organize and count a collection of counters.