Mental Math: Subtracting and Adding by 10

In this video with worksheet practice, the Kids Academy teacher, practices adding and subtracting 10 to a number. When adding or subtracting 10 to a number, students see that only the number in the tens place changes. With practice, students do these types of computations mentally.  A student’s number sense improves and adding and subtracting by 10, to and from any number, becomes easier.

The video teacher first works some examples on the whiteboard. After, he explains the worksheet. The task is to look at several equations and put a checkmark beside the equations that are correct.

Extension activities include using base 10 blocks to add 10 to a number as well as decomposing a number and then adding 10. Students see the relationship and patterns in numbers. This makes more complex operations easier as the student progresses to higher grades and levels.

Adding and subtracting 10 to a number improves number sense and encourages students to do more mental math.