9 − 7 = ＿ .
Nine take away seven equals what?
We can use a bar model to help think about this question. If we start with nine and we take away seven, how many will be left? We can also use a number line. We can start at nine and count back seven. Two, three, four, five, six, we landed on number two. Nine take away seven is two. The missing number is two.