### Spelling Circle

Find the words hidden inside each of the circles by counting around a certain number of spaces to find each letter in turn.

### Multiplication Squares

Can you work out the arrangement of the digits in the square so that the given products are correct? The numbers 1 - 9 may be used once and once only.

### What's in the Box?

This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?

# Turning Cogs

##### Age 7 to 11 Challenge Level:

Pick two cogs in the interactivity below, place them near each other and turn one of them.
What happens?
(You can turn a selected cog by using the arrow keys on your keyboard or by using the green arrows on the interactivity.)

Full Size Version

Now pick a different pair and do the same thing again.

What do you notice about the direction in which the cogs turn each time?

Now pick two cogs with 5 "teeth".
Mark a "tooth" on each cog by selecting it and then pressing the blue button. You may like to line up the marked teeth so that they start next to each other.
Watch what happens to the teeth that are marked as the two cogs turn.
What can you say about the way that the marked tooth of one cog fits into the gaps of the second cog?
Will this always be the case whichever two cogs you pick?