### Number Detective

Follow the clues to find the mystery number.

### Make 37

Four bags contain a large number of 1s, 3s, 5s and 7s. Pick any ten numbers from the bags above so that their total is 37.

### 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?

# Various Venns

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

Where would you put a number which is square but not odd?
Where would a square odd number go?
Where would a number which is odd but not square go?
Where would you put a number which is not square and not odd?
You could try placing each number in turn. For example, is $0$ a square number? Is it an odd number?