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

Start Practicing

Worksheet: Addition of Three Numbers within 20

Q1:

Hannah has 20 counters.

Use the counters to find the missing number.

Q2:

Find the missing number in 1 6 + 3 + 1 = + 1 .

Using that 1 6 + 3 + 1 = 1 9 + 1 , what is 1 6 + 3 + 1 ?

Q3:

Benjamin had 5 chocolate bars, 4 lollipops, and 3 gummy bears.

In total, he had 5 + 4 + 3 candies.

Find another way to write the total number of candies.

  • A 4 + 7
  • B 5 + 8
  • C 4 + 6
  • D 5 + 7
  • E 4 + 4 + 3

Q4:

Find the missing number in 1 3 + 4 + 7 = + 7 .

Q5:

We will see how we can write 4 + 6 + 3 in different ways.

Find the missing number.

Find the missing number.

Complete the missing sum.

  • A4, 8
  • B7, 3
  • C7, 6
  • D11, 3
  • E4, 9

All of these sums are equal. What are they equal to?

Q6:

When we add three numbers, we can first add any two of them.

For example, to find 8 + 6 + 7 , we could first add 8 and 6 to get 14 as the picture shows.

Now, can you find the missing number?

Q7:

Find the missing number.

Q8:

Am I using the equal sign correctly? Check if the two sums are equal.

  • A yes
  • B no