Change the stack's width with the − / + buttons (or drag right to widen, left to narrow) until the blocks form a full rectangle that exactly fills the glowing shelf. If the width doesn't fit, the top row stays incomplete — that's not a clean rectangle. Then press Check.
3D math game · Best for grades 3-5
Factris gives multiplication and factoring a Tetris-style twist. A fixed count of warehouse blocks must be arranged into a perfect rectangle that exactly fills a glowing shelf. Students find a working width — meaning a factor of the total — and the height fills in automatically, making the link between area, arrays, and multiplication facts vivid.
Factris builds fluency with factors, multiples, and the relationship between multiplication and area. Searching for a width that works is identical to finding a factor pair, so students internalise factor pairs through spatial trial and error rather than rote memorisation.
The shelf holds 12 blocks. Width 3 gives height 4 — the rectangle fills perfectly. Width 5 leaves 2 orphan blocks in the top row — not a factor. Students quickly learn that 1, 2, 3, 4, 6, and 12 all work; 5, 7, 8, 9, 10, 11 do not.
Students often try every number linearly instead of reasoning about factors. Noticing that width × height = total and using that to guess smarter widths is the insight the game is designed to surface.
Use it for individual practice, paired work, or a short class demonstration before worksheets.
Start with the game above, then continue with written practice to reinforce the skill.