Addition & subtraction strategies to solve two-digit equations using an open number line. In this lesson, students go over using different addition and subtraction strategies to solve two-digit ...

Addition involves finding the total of two or more numbers or amounts. There are different things you can use to help you add. You can use number lines, place value charts and place value counters.

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 ...