Solution

24925

First name
Henry Forster
School
Junior King's Canterbury
Age
11

On the third row down the triangle has to be in the three times table. Three doesn't work so I tryed 6 and it worked. From that I found that the circles are 4 because I knew that I could figure out what the square is which is 8. From that I worked out that the hexagon is 7. Add up a hexagon a triangle and 2 circles which is 21