Lesson: Subtracting Ones from Teen Numbers: Subtracting From Ten Elementary School Mathematics 1st Grade

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.

So .

Now you have a go. What is ?