# Worksheet: Subtracting by Adding with Numbers up to 20

In this worksheet, we will practice solving subtraction problems by finding the missing part in an addition expression with numbers up to 20.

**Q2: **

Isabella built 13 sandcastles on the beach. The tide came in and washed some of them away. There are 7 left and she wants to know how many were washed away.

Which of these number sentences does she need to solve?

- A
- B
- C
- D

Which of these addition facts can help her to solve the problem?

- A
- B
- C

How many sandcastles were washed away?

*Hint*: Use to solve .

**Q4: **

We know that .

What is ?**Q6: **

Which of the following addition sentences can help you solve ?

- A
- B
- C

What is the result of ?

**Q7: **

Complete the following using to help you: .

**Q8: **

Find the missing number in the given model.

Write an addition fact to prove your answer.

- A
- B
- C

**Q9: **

Which of the following calculations can help you check if is correct?

- A
- B
- C