### Calendar Capers

Choose any three by three square of dates on a calendar page...

Make a set of numbers that use all the digits from 1 to 9, once and once only. Add them up. The result is divisible by 9. Add each of the digits in the new number. What is their sum? Now try some other possibilities for yourself!

### Rotating Triangle

What happens to the perimeter of triangle ABC as the two smaller circles change size and roll around inside the bigger circle?

# Growing Ls

##### Stage: 3 Short Challenge Level:
See all short problems arranged by curriculum topic in the short problems collection

This is a size 1 L:

Four of them can be used to tile a size 2 L:

Devise a convincing argument that you will be able to tile a size 4, 8, 16, 32... $2^n$ L using size 1 Ls.

If you liked this question, here is an NRICH task which challenges you to use similar mathematical ideas.