## 100 Square Jigsaw

Use the interactivity below to complete the 100 square jigsaws. There are four different versions to try.

How are you going about this task? What are you looking for?

If you would prefer to work away from a screen, you could print off a sheet of the square and the pieces to cut out.

The printable sheets can be found here: Puzzle 1, Puzzle 2, Puzzle
3 and Puzzle 4.

### Why do this problem?

This jigsaw is a great way to reinforce children's understanding of the sequences contained within a hundred square. It could be used as an exploratory tool for children who haven't met the 0-99 hundred square before (puzzles 2 and 4 in the interactivity), or it could play a part in assessing their
understanding of it, if they have already met it.

### Possible approach

*This problem featured in an NRICH Primary webinar in September 2021.*

You could use one of the jigsaws as a whole class activity on an interactive whiteboard, inviting children to explain how they would start, and going on to complete the task altogether.

Alternatively, you could introduce a jigsaw to the whole group and then ask them to complete it in pairs, either on computers/tablets or by printing off and cutting out the sheets (Puzzle 1, Puzzle
2, Puzzle 3 and Puzzle 4) of the grid and pieces.

The conversations they have amongst each other as they work will be well worth listening in on!

### Key questions

What are you looking out for?

Which piece has the lowest number on it?

Which has the highest number?

How might that help us to complete the jigsaw?

Where will the smallest number go? How do you know?

### Possible support

Pupils could be prompted to find the 0 and 99 or the 1 and 100, looking at some completed number squares to see where these numbers usually go. They could be encouraged to find the numbers that go next to numbers that are already in place.

### Possible extension

Children could use a blank sheet of squared paper to make a hundred square with some numbers missing, or a differently sized numbered square such as 9 by 9 or 12 by 12.