Add Three Numbers

Grade 1 · mathematics · 91 practice problems · read aloud

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Adding Three Numbers

Adding three numbers means putting three groups together to find the total. We use this when we have more than two things to count up, like adding up all your toys from different boxes!

How to Add Three Numbers

  1. Step 1: Look at all three numbers you need to add.
  2. Step 2: Start by adding the first two numbers together.
  3. Step 3: Take that answer and add the third number to it.
  4. Step 4: You found the total! 🎉

Let's Try Some Examples!

Example 1: 2 + 3 + 4

  • First, add 2 + 3 = 5
  • Next, add 5 + 4 = 9
  • So, 2 + 3 + 4 = 9

Example 2: 1 + 5 + 2

  • First, add 1 + 5 = 6
  • Next, add 6 + 2 = 8
  • So, 1 + 5 + 2 = 8

Watch Out! Common Mistakes

Forgetting a Number: Sometimes kids add the first two numbers but forget to add the third one! Always make sure you add all three numbers in the problem.

Wrong Order: It doesn't matter which two numbers you add first! You can change the order to make it easier. For 2 + 7 + 8, you could add 2 + 8 first to make 10, then add 7.

Tips & Tricks

Look for 10: See if two of the numbers make 10 (like 3 and 7, or 1 and 9). Add those together first because 10 is easy to add to!

Count On: Start with the biggest number and count on the other two. For 4 + 2 + 3, start with 4, then count "5, 6" for the 2, then "7, 8, 9" for the 3.

Use Your Fingers: It's okay to use your fingers to help you keep track! 👍

How to Practice

  • Use small objects like blocks, buttons, or cereal. Make three groups and add them together.
  • Ask an adult to give you simple problems like "What is 2 apples + 3 apples + 1 apple?"
  • Play online math games for first grade addition.
  • Practice with flashcards that have three numbers to add.

Practice problems

6 of the 91, worked through step by step — try them before opening the answer.

1 7 + 4 + 3 = ?

Hint: Add the first two numbers together, then add that result to the third number.

Show the answer

Answer: 14

  1. Start with the first two numbers: 7 + 4. 7 + 4 = 11.
  2. Now take the result from Step 1 and add the third number: 11 + 3. 11 + 3 = 14.
  3. Final answer: 14.

Let's add the numbers step by step.

2 7 + 4 + 5 = ?

Hint: Add the first two numbers together, then add that result to the third number.

Show the answer

Answer: 16

  1. Start with the first two numbers: 7 + 4. 7 + 4 = 11.
  2. Now take the result from Step 1 and add the third number: 11 + 5. 11 + 5 = 16.
  3. Check the reasoning: We added 7 and 4 to get 11, then added 5 to get 16. This is correct because addition is done from left to right. Final Answer: 16

Let's add the numbers step by step.

3 8 + 2 + 5 = ?

Hint: Add the first two numbers together, then add the third number to your result.

Show the answer

Answer: 15

  1. Add the first two numbers: 8 + 2 = 10
  2. Add the third number to the result: 10 + 5 = 15

The answer is 15.

4 8 + 2 + 6 = ?

Hint: Add the first two numbers together, then add the third number to your result.

Show the answer

Answer: 16

  1. Add the first two numbers: 8 + 2 = 10
  2. Add the third number to your result: 10 + 6 = 16

The answer is 16.

5 6 + 4 + 8 = ?

Hint: Add the first two numbers together, then add the third number to that total

Show the answer

Answer: 18

  1. Add the first two numbers: 6 + 4 = 10
  2. Add the third number to the total: 10 + 8 = 18
  3. The final answer is 18

6 6 + 4 + 3 = ?

Hint: Add the first two numbers together, then add the third number to your result.

Show the answer

Answer: 13

  1. Add the first two numbers: 6 + 4 = 10
  2. Add the third number to your result: 10 + 3 = 13

The answer is 13.

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