Learners hone their math skills with this two less within 20 worksheet. Students understand that less than indicates subtraction. So they take away the said amount from the given number. They may count back from the given number to get to the result. In two less within 20 worksheet, students get plenty of practice with this concept. This worksheet is about practicing the column method in which numbers are written one on top of another. In this method, students use their place value understanding to solve the problems.