### Number Detective

Follow the clues to find the mystery number.

### Red Even

You have 4 red and 5 blue counters. How many ways can they be placed on a 3 by 3 grid so that all the rows columns and diagonals have an even number of red counters?

### Prime Magic

Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3 grid so that all the rows and columns add up to a prime number. How many different solutions can you find?

# Three Spinners

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

This is a number spinner. When you spin it, it can land on any number from one to ten.

Here are three more number spinners with ten numbers on them. But you cannot see what the numbers are.

I spun the red one $15$ times and got these numbers:

I spun the blue one $15$ times and the yellow one $15$ times and got these numbers:

Then I did the same things again twice over. I got these numbers, but forgot to note which numbers came from which spinner:

Can you work out which spinner generated each list? How did you do it?

We could call the numbers on the first spinner "Numbers from one to ten".

Can you think of a title for the set of numbers on the red spinner?

Can you think of titles for the sets of numbers on the blue and the yellow spinners?