Add Multiples of 10

lessonbunny.com

Answer Key & Explanations

Add Multiples of 10 · Grade 1 · Worksheet 3

1. A square garden has 4 equal sides. Each side is 10 feet long. What is the total distance around the garden? Answer: 40 Solution: A square has 4 equal sides. Each side is 10 feet long.
   Full step-by-step solution

   Step 1: A square has 4 equal sides. Step 2: Each side is 10 feet long. Step 3: To find the total distance around, add all four sides: 10 + 10 + 10 + 10 Step 4: 10 + 10 = 20, then 20 + 10 = 30, then 30 + 10 = 40 Step 5: The total distance around the garden is 40 feet.

2. Mason drew 9 towers of base-ten blocks. Each tower has 10 blocks. How many blocks did Mason draw in all? Answer: 90 Solution: Mason has 9 towers, and each tower has 10 blocks. This means we need to add 10 nine times, or multiply 9 by 10. 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 = 90 Or, 9 times 10 equals 90.
   Full step-by-step solution

   Step 1: Mason has 9 towers, and each tower has 10 blocks. Step 2: This means we need to add 10 nine times, or multiply 9 by 10. Step 3: 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 = 90 Step 4: Or, 9 times 10 equals 90. Step 5: Mason drew 90 blocks in all. The answer is 90.

3. Emma had 40 crayons in her art box. Her grandmother bought her 50 more crayons for her birthday. How many crayons does Emma have now? Answer: 90 Solution: Emma started with 40 crayons She received 50 more crayons Add the two amounts: 40 + 50 40 + 50 = 90 The answer is 90.
   Full step-by-step solution

   Step 1: Emma started with 40 crayons Step 2: She received 50 more crayons Step 3: Add the two amounts: 40 + 50 Step 4: 40 + 50 = 90 The answer is 90.

4. A triangle has 3 sides. One side is 10 cm long, another side is 20 cm long, and the third side is 30 cm long. What is the total length of all three sides of the triangle? Answer: 60 Solution: The first side is 10 cm long. The second side is 20 cm long. Add this to the first side: 10 + 20 = 30.
   Full step-by-step solution

   Step 1: The first side is 10 cm long. Step 2: The second side is 20 cm long. Add this to the first side: 10 + 20 = 30. Step 3: The third side is 30 cm long. Add this to the total so far: 30 + 30 = 60. The total length of all three sides is 60 cm.

5. 30 + 40 = ? Answer: 70 Solution: Identify the numbers to be added. We have 30 and 40. Add the numbers in the ones place first.
   Full step-by-step solution

   Step 1: Identify the numbers to be added. We have 30 and 40. Step 2: Add the numbers in the ones place first. The number 30 has a 0 in the ones place. The number 40 also has a 0 in the ones place. 0 + 0 = 0 So, the ones digit of our answer is 0. Step 3: Add the numbers in the tens place. The number 30 has a 3 in the tens place, which represents 3 tens, or 30. The number 40 has a 4 in the tens place, which represents 4 tens, or 40. 3 tens + 4 tens = 7 tens, or 70. Step 4: Combine the results from the tens and ones places. From Step 3, we have 7 tens (70). From Step 2, we have 0 ones (0). 70 + 0 = 70. Step 5: State the final answer. Therefore, 30 + 40 = 70.

6. Liam has 40 toy cars in his collection. For his birthday, his aunt gives him 30 more toy cars. How many toy cars does Liam have now? Answer: 70 Solution: Liam starts with 40 toy cars He receives 30 more toy cars Add the two amounts: 40 + 30 40 + 30 = 70 The answer is 70.
   Full step-by-step solution

   Step 1: Liam starts with 40 toy cars Step 2: He receives 30 more toy cars Step 3: Add the two amounts: 40 + 30 Step 4: 40 + 30 = 70 The answer is 70.

7. Kaia has 50 stickers. Kaia's friend gives Kaia 30 more stickers. How many stickers does Kaia have in all? Answer: 80 Solution: Kaia starts with 50 stickers. Kaia receives 30 more stickers. Add them together: 50 + 30 = 80.
   Full step-by-step solution

   Step 1: Kaia starts with 50 stickers. Step 2: Kaia receives 30 more stickers. Step 3: Add them together: 50 + 30 = 80. Kaia has 80 stickers in all.

8. A triangle has 3 sides. One side is 10 cm long, another side is 20 cm long, and the third side is 30 cm long. What is the total length around the triangle? Answer: 60 Solution: The first side is 10 cm The second side is 20 cm The third side is 30 cm Add all the sides together: 10 + 20 + 30 10 + 20 = 30 30 + 30 = 60 The answer is 60 cm.
   Full step-by-step solution

   Step 1: The first side is 10 cm Step 2: The second side is 20 cm Step 3: The third side is 30 cm Step 4: Add all the sides together: 10 + 20 + 30 Step 5: 10 + 20 = 30 Step 6: 30 + 30 = 60 The answer is 60 cm.

9. Aroha drew 6 stacks of base-ten blocks. Each stack has 10 blocks. Then she drew 4 more stacks of ten blocks next to them. How many blocks did Aroha draw in total? Answer: 100 Solution: Aroha has 6 stacks of ten blocks. 6 tens is 60 blocks. She also has 4 stacks of ten blocks.
   Full step-by-step solution

   Step 1: Aroha has 6 stacks of ten blocks. 6 tens is 60 blocks. Step 2: She also has 4 stacks of ten blocks. 4 tens is 40 blocks. Step 3: Add the two amounts: 60 + 40 = 100. Step 4: Aroha drew 100 blocks in total. The answer is 100.