Lots of solutions were sent in for these!
Well done to Syed from Foxford School and Community College, Jason from Priory School, Christina from London, William and Luke from Radwinter Primary and Samantha from Nanyang Primary, Singapore. Well done also to Katy.
Oliver, Anuradha and Yogun from Bancrofts Prep, Woodford Green said:
We worked it out by adding the possible numbers until we got 15.
It is a bit like Quinze, a game we have played at school.
Anuradha noticed that:In the first square, the numbers going left to right are the same as the number going down the columns in the second square.
Also, the numbers going down the column in the 1 st square, read left to right in the second square.