imc

Let the number be $10a+b$ where $a$ and $b$ are the tens and units digits of the number. So $(10a+b)-(a+b)=9a$ must have a units digit of $6$ This is only possible if $9a=36$, so $a=4$ is the only way this can be true. So the numbers that have this property are $40,41,42,43,44,45,46,47,48,49$. Therefore the answer is $\boxed{10}$