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Number Detective

Follow the clues to find the mystery number.


There are exactly 3 ways to add 4 odd numbers to get 10. Find all the ways of adding 8 odd numbers to get 20. To be sure of getting all the solutions you will need to be systematic. What about a total of 15 with 6 odd numbers?

Great Granddad

Great Granddad is very proud of his telegram from the Queen congratulating him on his hundredth birthday and he has friends who are even older than he is... When was he born?

More Carroll Diagrams

Age 7 to 14 Challenge Level:

Can you put the numbers in the correct place in this Carroll diagram?

You could print off this sheet.pdf.

Can you explain how you know where to place the numbers?


Now have a look at this Carroll diagram. This time, the idea is to fill in the labels for the rows and columns.

You could print off sheet.pdf to complete.