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 ...

You can find the difference between two numbers in more than one way. You can count up from the smaller number to the larger number. Or, you can count back from the larger number to the smaller number ...

To add -4 and 5, draw the starting number on a number line and count to the right when adding numbers. What is the difference in temperature between a desert at 40 °C and a mountain top at -2 °C? \(40 ...