Robert from Matthew Pearce Public School sent a solution to the first part of this problem. Robert says:put $3, 9, 5, 7, 1$ in odd numbers and less than ten
So, the completed Carroll diagram would look like this:
Well done also to Eliza from Danebank School who also completed this diagram.
Rowena from Christ Church Primary told us how she went about filling in the second Carroll diagram:
Here is a picture of Rowena's completed diagram:
You've explained this very well, Rowena. It's interesting that you've decided that the numbers $1-9$ have zero as their tens digit and that zero is even. Perhaps some of you have comments about this?