The children found starting this problem a bit tricky and were unsure about how to approach it. Once they had fully understood what it was the problem was asking them to do, and with a small amount of guidance, a lot of children started working away at it in a very logical way.
The majority of us started by finding the sums that would answer each of the pairs of cards. Once we had a full list for each card pairing, we worked our way through filling each of the cards. This part was a little bit frustrating as we couldn't use a number more than once. A lot of times, as we neared an answer, the same number would pop up and we would have to start again!
As a result of the amount of sums for each pairing, we had a variety of solutions within the class.