### Pebbles

Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?

### It Figures

Suppose we allow ourselves to use three numbers less than 10 and multiply them together. How many different products can you find? How do you know you've got them all?

### Bracelets

Investigate the different shaped bracelets you could make from 18 different spherical beads. How do they compare if you use 24 beads?

# A Dotty Problem

## A Dotty Problem

Starting with the number $180$, take away $9$ again and again, joining up the dots as you go.

Watch out - don't join all the dots!

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### Why do this problem?

This problem is a different way of practising the nine times table. It also provides a context in which you can discuss mental strategies for taking away nine.

### Key questions

What do you get if you take away nine from that number?
How could you work it out?
Can you think of another way to do it?

### Possible extension

Children could make their own version for counting backwards in twelves.