Addition with Blocks

Arithmetic · Axiom Academy

Build addition problems with two groups of blocks and read off the sum. Addition means combining two groups into one total. Start with a group of blue blocks and a group of orange blocks, push them together, and count the whole collection. That count is the sum — and you can see it happen. Watch a group of 3 blocks join a group of 2 blocks . As they slide together into one pile, the running count climbs — and settles on 5 . That total is the sum, written 3 + 2 = 5 . Addition puts groups together. The sum is always at least as large as either group you started with. Drag a slider to add or remove blocks in each group. The two groups push together into a total, and the equation underneath updates as you build — so you can see exactly how the sum follows from the two groups. Count the blocks in Group 1, then keep counting through Group 2. The last number you say is the sum. You just saw and built what addition really is: combining two groups into one total, where the sum is never smaller than either group you started with. Blocks make it visible — but the same idea works for any two numbers.

This is the written version of the interactive lesson above. See the full Arithmetic course.