### Calendar Capers

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

### Card Trick 2

Can you explain how this card trick works?

### Happy Numbers

Take any whole number between 1 and 999, add the squares of the digits to get a new number. Make some conjectures about what happens in general.

# Latin Numbers

##### Stage: 3 Challenge Level:

Here is an example of a 4 by 4 Latin square:

Can you see what is going on?

In a Latin Square each symbol or colour occurs exactly once in each row and exactly once in each column.

In the grid below, N is a 6 digit number with a very special property:
if you double the number and write it in the second row,
treble the number and write it in the third row,
and so on...
you end up with a Latin Square!

Can you find the six digit number N?

If you're finding it difficult to get started, click below to see a diagram showing one possible order in which you can work out each value.

Work out the number in the pale blue cell first.
Then the numbers in the column marked "2nd", then "3rd" and so on...

 1st 3rd 4th 5th 2nd

There is some more advice in the Getting Started section.