Solution

155043

First name
Tommy Farmer
School
St Georges, Bickley, Primary
Age
11
Email address
sally.bellchambers@btinternet.com

I knew as it ended in 0.125 that it had to be something divided by 8. So I calculated the inverse, ie, 3.125 x 8 and it gives an answer of 25.

So 25 divided by 8 (both numbers under 50) = 3.125.