We had correct solutions to this problem from Rebecca age 5 who goes to Lexden Primary School, and also from Jake, Sam, Rebecca, Ryo, Luke, Katie and Charlie from Moorfields Junior School. Ryo and Luke explain how they arrived at the answer:

We used 10 and 5 for 15, 10 and 6 for 16, 10 and 2 for 12, 10 and 9 for 19, 10 and 4 for 14, 10 and 1 for 11, 10 and 7 for 17 so we did not use 10 and 3.

Rebecca from Lexden Primary goes on to say:

The flower number 18 has no butterflies. It needs a 10 and a 8.