Open Number Lines 2 | 2nd Grade Math Special | 28m 38s Video has Closed Captions | CC In this lesson, students go over using different addition and subtraction strategies to solve two-digit ...

Using subtraction. There are two ways to find the answer to subtraction calculations. First, you could start on the smaller number and count up to reach the bigger number.

Open Number Lines 4 | 2nd Grade Math. Special | 28m 56s Video has Closed Captions | CC. Addition & subtraction strategies to solve two-digit equations using an open number line.

Empty number lines can help you work out the difference between the two numbers. For example, if you want to work out 72 - 64, you begin on 64 and count up. Like this: ...