"We did this sum at school last year and this is what I think the answer is. First I did this kind of boxes. They were 4 squares down, 1 square at the top left and one at the bottom right. I looked for more and I found that there was only 1:
Then I did this kind of boxes. They were 4 squares down, then one square
at the left and opposite it the right one. There were 2 of these:
After that I did this kind of boxes. They were 4 squares down, 1 square at the left and then a right square which will be opposite then 1 square up or down. There were 2 of these:
Fourthly I did this kind of boxes. They were 4 squares down, 1 square at the left and a right one which will be opposite then 2 squares up or down. There was only 1 of them: At last I did this kind of boxes. They were 3 squares down and 3 squares which the last of their square is touching the last of the 1st 3 squares. There was only one of them:
The answer is you can make 7 boxes".
Jannis (Long Bay Primary) then correctly found the other 4:
Finally, Matthew (Eastwood Primary) noticed that:
"You can turn them around or reflect them to make a lot more."