Lesson: Subtraction of 7, 8, or 9 from Teen Numbers
In this lesson, we will learn how to use the decomposition of teen numbers into tens and ones to help subtract 7, 8, or 9 from numbers between 11 and 20.
Sample Question Videos
Worksheet: 4 Questions • 3 Videos
Which addition expression is equal to ?
Think about taking away 9 from different numbers.
For example, the pictures show that 10 take away 9 is 1 and 11 take away 9 is .
Look at these number sentences. Which one is WRONG?
Let us try to find 13 take away 9.
We can draw 13 dots as one group of 10 dots and one group of 3 dots.
Now take away 9 from the group of ten dots.
We are left with dots which is 4 dots.
Now you have a go. What is ?