Adding Numbers to 20

Grade 1 · Math · Study Guide

Learn how to add two numbers together with sums up to 20.

Addition means putting two groups of things together to find out how many you have in all. When you add, you start with one number and count on to find the total. The answer to an addition problem is called the sum.

You can use many strategies to add. One way is to count on your fingers. If you have 6 apples and get 4 more, you start at 6 and count up: 7, 8, 9, 10. Another way is to use a number line — just hop forward the second number of spaces. You can also draw pictures to help!

Addition problems use a plus sign (+) to show we are adding, and an equal sign (=) to show the answer. For example: 7 + 5 = 12. The numbers being added are called addends, and the result is the sum. Knowing addition facts up to 20 helps you in everyday life — like counting toys, sharing snacks, or keeping score in a game!

Key terms

Addition
Putting two groups together to find the total amount.
Addend
The numbers you add together in an addition problem.
Sum
The answer you get when you add two or more numbers.
Plus Sign (+)
The symbol that means you are adding two numbers together.
Equal Sign (=)
The symbol that means the two sides have the same value.

Flashcards

5 + 5
10
6 + 6
12
7 + 7
14
8 + 8
16
9 + 9
18
10 + 10
20
Addend
A number you add to another number.
Sum
The answer when you add two numbers together.

Questions

  1. What is 8 + 5?

    1. 12
    2. 13
    3. 14
    4. 11
    Show answer

    Answer: 13

    8 + 5 = 13. Start at 8 and count up 5: 9, 10, 11, 12, 13.

  2. The sum of 9 + 9 is 18.

    Show answer

    Answer: True

    9 + 9 = 18. Adding the same number twice is called doubling.

  3. What is 6 + 7?

    1. 12
    2. 14
    3. 13
    4. 11
    Show answer

    Answer: 13

    6 + 7 = 13. Start at 6 and count up 7 more to reach 13.

  4. The answer to an addition problem is called the ___.

    Show answer

    Answer: sum

    The sum is the total you get when you add numbers together.

  5. Which addition sentence equals 15?

    1. 7 + 9
    2. 8 + 8
    3. 6 + 9
    4. 7 + 7
    Show answer

    Answer: 6 + 9

    6 + 9 = 15. Check: 7 + 9 = 16, 8 + 8 = 16, 7 + 7 = 14. Only 6 + 9 equals 15.

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