Lesson Worksheet: Subtracting by Adding with Numbers up to 20 Mathematics • 1st Grade

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


Matthew had 17 toy cars.

He lost 6 of the cars.

He can work out how many cars are left by completing either number sentence: 176=,6+=17.

How many cars are left?


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?

  • A137=
  • B7+13=
  • C713=
  • D13+7=

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

  • A7+6=13
  • B13+7=20
  • C6+13=19

How many sandcastles were washed away?

Hint: Use 7+6=13 to solve 137=.


Hannah and Anthony made 19 cupcakes.

After their dog ate some, there were 15 left.

They want to know how many cakes their dog ate.

Who is correct?

  • Aonly Anthony
  • BThey are both wrong.
  • CThey are both correct.
  • Donly Hannah


We know that 4+9=13.

What is 139?


We know that 5+7=12.

What is 127?


Which of the following addition sentences can help you solve 195?

  • A19+14
  • B19+5
  • C5+14

What is the result of 195?


Complete the following using 19=5+14 to help you: 195=.


Find the missing number in the given model.

Write an addition fact to prove your answer.

  • A9+9=18
  • B9+8=18
  • C18+9=9


Which of the following calculations can help you check if 125=7 is correct?

  • A12+5=7
  • B12+7=5
  • C5+7=12

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.