Add Three Numbers

lessonbunny.com

Answer Key & Explanations

Add Three Numbers · Grade 1 · Worksheet 1

1. 7 + 8 + 4 = ? Answer: 19 Solution: Add the first two numbers: 7 + 8 = 15 Add the third number to the result: 15 + 4 = 19 The answer is 19.
   Full step-by-step solution

   Step 1: Add the first two numbers: 7 + 8 = 15 Step 2: Add the third number to the result: 15 + 4 = 19 The answer is 19.

2. Hana has 4 red balloons, 6 blue balloons, and 2 yellow balloons. How many balloons does Hana have in total? Answer: 12 Solution: Start with the red balloons: 4 Add the blue balloons: 4 + 6 = 10 Add the yellow balloons: 10 + 2 = 12 Hana has 12 balloons in total.
   Full step-by-step solution

   Step 1: Start with the red balloons: 4 Step 2: Add the blue balloons: 4 + 6 = 10 Step 3: Add the yellow balloons: 10 + 2 = 12 Hana has 12 balloons in total. The answer is 12.

3. 6 + 4 + 8 = ? Answer: 18 Solution: Add the first two numbers: 6 + 4 = 10 Add the third number to the total: 10 + 8 = 18 The final answer is 18
   Full step-by-step solution

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

4. Sara has 6 crayons. Her friend gives her 4 more crayons. Then her teacher gives her 3 more crayons. How many crayons does Sara have now? Answer: 13 Solution: Sara starts with 6 crayons Her friend gives her 4 more crayons: 6 + 4 = 10 Her teacher gives her 3 more crayons: 10 + 3 = 13 Sara now has 13 crayons total The answer is 13.
   Full step-by-step solution

   Step 1: Sara starts with 6 crayons Step 2: Her friend gives her 4 more crayons: 6 + 4 = 10 Step 3: Her teacher gives her 3 more crayons: 10 + 3 = 13 Step 4: Sara now has 13 crayons total The answer is 13.

5. Olivia has 7 red balloons, 5 blue balloons, and 3 green balloons. How many balloons does Olivia have in all? Answer: 15 Solution: Start with the red balloons: 7 Add the blue balloons: 7 + 5 = 12 Add the green balloons: 12 + 3 = 15 Olivia has 15 balloons in all.
   Full step-by-step solution

   Step 1: Start with the red balloons: 7 Step 2: Add the blue balloons: 7 + 5 = 12 Step 3: Add the green balloons: 12 + 3 = 15 Olivia has 15 balloons in all. The answer is 15.

6. Noah has 6 red balloons. His friend Sophia gives him 1 blue balloon. Then Ava gives him 1 green balloon. How many balloons does Noah have in total? Answer: 8 Solution: Noah starts with 6 red balloons. Sophia gives him 1 blue balloon: 6 + 1 = 7 Ava gives him 1 green balloon: 7 + 1 = 8 Noah has 8 balloons in total.
   Full step-by-step solution

   Step 1: Noah starts with 6 red balloons. Step 2: Sophia gives him 1 blue balloon: 6 + 1 = 7 Step 3: Ava gives him 1 green balloon: 7 + 1 = 8 Noah has 8 balloons in total.

7. There are 6 red blocks in the first row, 5 blue blocks in the second row, and 4 yellow blocks in the third row. How many blocks are there in all? Answer: 15 Solution: Count the red blocks: 6 Count the blue blocks: 5 Count the yellow blocks: 4 Add all the blocks together: 6 + 5 + 4 First add 6 + 5 = 11 Then add 11 + 4 = 15 The answer is 15.
   Full step-by-step solution

   Step 1: Count the red blocks: 6 Step 2: Count the blue blocks: 5 Step 3: Count the yellow blocks: 4 Step 4: Add all the blocks together: 6 + 5 + 4 Step 5: First add 6 + 5 = 11 Step 6: Then add 11 + 4 = 15 The answer is 15.

8. Liam has 4 toy cars. His friend Noah gives him 3 more toy cars, and then his sister Emma gives him 2 more. How many toy cars does Liam have now? Answer: 9 Solution: Liam starts with 4 toy cars. So, initial number of cars = 4. Noah gives him 3 more toy cars.
   Full step-by-step solution

   Let's solve this step by step. Step 1: Liam starts with 4 toy cars. So, initial number of cars = 4. Step 2: Noah gives him 3 more toy cars. We add 3 to the initial amount: 4 + 3 = 7 toy cars. Step 3: Emma gives him 2 more toy cars. We add 2 to the current amount: 7 + 2 = 9 toy cars. Step 4: Conclusion. After receiving cars from Noah and Emma, Liam has 9 toy cars. Final answer: 9

9. 7 + 4 + 5 = ? Answer: 16 Solution: Start with the first two numbers: 7 + 4. 7 + 4 = 11. Now take the result from Step 1 and add the third number: 11 + 5.
   Full step-by-step solution

   Let's add the numbers step by step. Step 1: Start with the first two numbers: 7 + 4. 7 + 4 = 11. Step 2: Now take the result from Step 1 and add the third number: 11 + 5. 11 + 5 = 16. Step 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

10. Mason has 2 red crayons, 7 blue crayons, and 2 green crayons. How many crayons does Mason have in all? Answer: 11 Solution: Start with the red crayons: 2 Add the blue crayons: 2 + 7 = 9 Add the green crayons: 9 + 2 = 11 Mason has 11 crayons in all.
    Full step-by-step solution

    Step 1: Start with the red crayons: 2 Step 2: Add the blue crayons: 2 + 7 = 9 Step 3: Add the green crayons: 9 + 2 = 11 Mason has 11 crayons in all. The answer is 11.