A number line can be useful when answering questions involving negative numbers. When adding a positive number, go up the number line (move to the right). When subtracting a positive number, go down ...

Addition and subtraction with regrouping using different strategies to solve. In this lesson, students go over addition and subtraction with regrouping using different strategies to solve. Today we ...

When you subtract using large numbers, it's often better to use a written method. Column subtraction is a good written method to take one number away from another. It involves writing the smaller ...