# Lesson Worksheet: Subtracting by Counting Back: Numbers up to 20 Mathematics • 1st Grade

In this worksheet, we will practice subtracting within 20 by counting back from the starting number.

**Q4: **

This is a subtraction machine.

It subtracts 3 from any number you put in.

What number will come out if you put 8 in?

What number will come out if you put 11 in?

What number will come out if you put 19 in?

**Q5: **

Hannah is playing a game using number cards. She steps on a number and jumps to land on another number. If Hannah steps on number 18 and jumps backward 4 jumps, which number will she land on?

**Q6: **

Olivia and Mason had 12 cookies. They ate some for breakfast. The picture shows the cookies left over. How many cookies did they eat?

**Q7: **

If there should be 12 counters in the given model, how many counters are missing?

**Q8: **

Complete the missing values in the figure from left to right.

- A8, 7, 6
- B10, 9, 8
- C9, 8, 7

**Q9: **

To find 19 take away 6, we can start at 19 and count backward 6.

Finish counting backward to find the answer to 19 take away 6.

**Q10: **

Jacob has two cards. Each card has a number on it. If the sum of the numbers on the two cards is 13, what is the missing number on the other card?