Simultaneous equations

We appear to have six simultaneous equations in three unknowns. That's overdetermined. But as it's intended for chidren aged no more than 11, maybe overdetermined is good – they'll have more ways to get at the answer.

We soon find that no solution is possible. That's hardly surprising; with an overdetermined set of equations, the solution set is likely to be empty. But that means it's not a suitable puzzle for 11-year-olds and younger. Let's have another think.

If we regard the first letter of each of the first three lines as an arbitrary label, unrelated to the variable of the same name; and the first "=" of those lines as a misshapen colon; the equations become

A+B=6
B+C=8
A÷B=2

Encouragingly, this set of three equations has a unique solution.