Can I show a 120 square?

Yes. One tap switches between 1 to 100, 1 to 120 and 0 to 99.

Can children come up and use it?

Yes. The targets are large, and two children can work on the board at the same time.

Can I clear just one colour?

Tapping a step button again clears that pattern. Undo steps back through individual changes, and Clear removes all the shading.

Interactive 100 Square

Number · Year 1–Year 5

Shade, hide and reveal. Multiples, counting patterns and number bonds.

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About the 100 square

Tap squares to shade them, or drag across the grid to shade a whole run at once. Dragging is much quicker than tapping when you are counting in steps.

The step buttons shade every multiple in one go. Put the 5s in one colour, then the 3s in another, and the multiples of 15 end up in the second colour. That is usually enough for a class to start describing the pattern before anyone names it.

Hide the numbers to turn the same grid into a blank hundred square for estimating and positioning, then reveal them to check.

Three grids are available. The usual 1 to 100, a 1 to 120 for crossing the hundred, and a 0 to 99 where every column shares a units digit and every row shares a tens digit.

How to use it on your whiteboard

1Tap a square to shade it. Tap it again to clear it.
2Drag across several squares to shade them together. That counts as one action, so one Undo clears the lot.
3Pick another colour to shade a second pattern over the first.
4Tap a step button, 2s through to 10s, to shade all its multiples. Tap it again to clear them.
5Use Hide for a blank grid, then Show to reveal the numbers and check.

Questions

Can I show a 120 square?: Yes. One tap switches between 1 to 100, 1 to 120 and 0 to 99.
Can children come up and use it?: Yes. The targets are large, and two children can work on the board at the same time.
Can I clear just one colour?: Tapping a step button again clears that pattern. Undo steps back through individual changes, and Clear removes all the shading.