In reply to @alexbellos
@alexbellos I must be missing something - in the top row, how can a two-digit number + 1 equal a one-digit number?
In reply to @christianp
@alexbellos never mind, it's numbers up to 16,not digits! Whoops!
In reply to @alexbellos
@alexbellos I must be missing something - in the top row, how can a two-digit number + 1 equal a one-digit number?
In reply to @christianp
@alexbellos never mind, it's numbers up to 16,not digits! Whoops!