Solution

160413

First name
Y6 Genius
School
Brudenell Primary
Country
Age
11

The functions that lie in between 'Think of a number' and 'subtract the starting number' will always make 5. This can be shown by looking at the following calculation:

(3 x 2 + 4) divide 2 = 5

The think of a number and subtraction of the original number cancel each other out, leaving a difference of 5.