John meant to divide a number by $2$, but he was careless and subtracted $2$ from the number instead.  He got an answer of $22$.  What would his answer have been had he actually divided by $2$ instead of subtracting $2$?
If he subtracted $2$ from the number and got $22$, then I can add $2$ to $22$ to get the number back. So, the number was $22 + 2 = 24$. Now, I need to divide this number by $2$ to see what John would have gotten. So, the correct answer is $24 \div 2 = 12$. 