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Add Three Numbers

Grade 1 · Mathematics · Worksheet 3

  1. 3 + 5 + 7 = ? Answer: ______________
  2. A triangle has sides of length 5 cm, 6 cm, and 7 cm. What is the perimeter of the triangle?
    Answer: ______________
  3. There are 5 red circles in the first row, 3 blue circles in the second row, and 2 green circles in the third row. How many circles are there in all? Answer: ______________
  4. Matiu has 6 red blocks, 4 blue blocks, and 8 yellow blocks. How many blocks does Matiu have in all? Answer: ______________
  5. 6 + 4 + 3 = ? Answer: ______________
  6. 8 + 2 + 6 = ? Answer: ______________
  7. 3 + 4 + 2 = ? Answer: ______________
  8. At the school fair, Emma won 7 tickets from the ring toss game. Then she won 4 more tickets from the bean bag toss. Finally, her friend gave her 3 extra tickets. How many tickets does Emma have altogether? Answer: ______________
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Answer Key & Explanations

Add Three Numbers · Grade 1 · Worksheet 3

  1. 3 + 5 + 7 = ? Answer: 15 Solution: Add the first two numbers: 3 + 5 = 8 Add the third number to the result: 8 + 7 = 15 The answer is 15.
    Full step-by-step solution

    Step 1: Add the first two numbers: 3 + 5 = 8 Step 2: Add the third number to the result: 8 + 7 = 15 The answer is 15.

  2. A triangle has sides of length 5 cm, 6 cm, and 7 cm. What is the perimeter of the triangle? Answer: 18 Solution: Identify the three side lengths: 5 cm, 6 cm, and 7 cm. Add the first two sides: 5 + 6 = 11. Add the third side to the sum: 11 + 7 = 18.
    Full step-by-step solution

    Step 1: Identify the three side lengths: 5 cm, 6 cm, and 7 cm. Step 2: Add the first two sides: 5 + 6 = 11. Step 3: Add the third side to the sum: 11 + 7 = 18. The perimeter is 18 cm.

  3. There are 5 red circles in the first row, 3 blue circles in the second row, and 2 green circles in the third row. How many circles are there in all? Answer: 10 Solution: Count the red circles in the first row: 5 Count the blue circles in the second row: 3 Count the green circles in the third row: 2 Add all the circles together: 5 + 3 + 2 First add 5 + 3 = 8 Then add 8 + 2 = 10 The answer is 10.
    Full step-by-step solution

    Step 1: Count the red circles in the first row: 5 Step 2: Count the blue circles in the second row: 3 Step 3: Count the green circles in the third row: 2 Step 4: Add all the circles together: 5 + 3 + 2 Step 5: First add 5 + 3 = 8 Step 6: Then add 8 + 2 = 10 The answer is 10.

  4. Matiu has 6 red blocks, 4 blue blocks, and 8 yellow blocks. How many blocks does Matiu have in all? Answer: 18 Solution: Start with the red blocks: 6. Add the blue blocks: 6 + 4 = 10. Add the yellow blocks: 10 + 8 = 18.
    Full step-by-step solution

    Step 1: Start with the red blocks: 6. Step 2: Add the blue blocks: 6 + 4 = 10. Step 3: Add the yellow blocks: 10 + 8 = 18. Matiu has 18 blocks in all.

  5. 6 + 4 + 3 = ? Answer: 13 Solution: Add the first two numbers: 6 + 4 = 10 Add the third number to your result: 10 + 3 = 13 The answer is 13.
    Full step-by-step solution

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

  6. 8 + 2 + 6 = ? Answer: 16 Solution: Add the first two numbers: 8 + 2 = 10 Add the third number to your result: 10 + 6 = 16 The answer is 16.
    Full step-by-step solution

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

  7. 3 + 4 + 2 = ? Answer: 9 Solution: Add the first two numbers: 3 + 4 = 7 Add the third number to the result from Step 1: 7 + 2 = 9 The answer is 9.
    Full step-by-step solution

    Step 1: Add the first two numbers: 3 + 4 = 7 Step 2: Add the third number to the result from Step 1: 7 + 2 = 9 The answer is 9.

  8. At the school fair, Emma won 7 tickets from the ring toss game. Then she won 4 more tickets from the bean bag toss. Finally, her friend gave her 3 extra tickets. How many tickets does Emma have altogether? Answer: 14 Solution: Emma started with 7 tickets from the ring toss She won 4 more tickets from the bean bag toss: 7 + 4 = 11 Her friend gave her 3 extra tickets: 11 + 3 = 14 Emma has 14 tickets in total
    Full step-by-step solution

    Step 1: Emma started with 7 tickets from the ring toss Step 2: She won 4 more tickets from the bean bag toss: 7 + 4 = 11 Step 3: Her friend gave her 3 extra tickets: 11 + 3 = 14 Step 4: Emma has 14 tickets in total