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Mental Math 10 More/Less

Grade 1 · Mathematics · Worksheet 2

  1. There are 3 rows of chairs. Each row has 4 chairs. How many chairs are there in total?
    Answer: ______________
  2. Aroha has 73 building blocks in her toy box. She gives 10 blocks to her little brother to play with. How many building blocks does Aroha have left? Answer: ______________
  3. Emma has 12 crayons in her box. She finds 10 more crayons under her desk. How many crayons does Emma have now? Answer: ______________
  4. Aroha is reading a book that has 83 pages. She has already read 73 pages. How many more pages does she need to read to finish the book? Answer: ______________
  5. Tane has 34 building blocks. His sister gives him 10 more blocks. How many building blocks does Tane have now? Answer: ______________
  6. 3 + 10 = ? Answer: ______________
  7. A farmer has 15 apples in a basket. If he picks 10 more apples from his tree, how many apples does he have now? Answer: ______________
  8. A baker had 14 cookies on a tray. She baked 10 more cookies. How many cookies are on the tray now? Answer: ______________
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Answer Key & Explanations

Mental Math 10 More/Less · Grade 1 · Worksheet 2

  1. There are 3 rows of chairs. Each row has 4 chairs. How many chairs are there in total? Answer: 12 Solution: We have 3 rows of chairs, and each row contains 4 chairs. We need to find the total number of chairs. Decide on the operation.
    Full step-by-step solution

    Step 1: Understand the problem. We have 3 rows of chairs, and each row contains 4 chairs. We need to find the total number of chairs. Step 2: Decide on the operation. Since we have equal groups (each row has the same number of chairs), we can use multiplication. Step 3: Write the multiplication expression. Number of rows = 3 Chairs per row = 4 Total chairs = 3 × 4 Step 4: Perform the multiplication. 3 × 4 = 12 Step 5: State the final answer. There are 12 chairs in total.

  2. Aroha has 73 building blocks in her toy box. She gives 10 blocks to her little brother to play with. How many building blocks does Aroha have left? Answer: 63 Solution: Aroha starts with 73 building blocks. She gives away 10 blocks, so we subtract: 73 - 10. 73 has 7 tens and 3 ones.
    Full step-by-step solution

    Step 1: Aroha starts with 73 building blocks. Step 2: She gives away 10 blocks, so we subtract: 73 - 10. Step 3: 73 has 7 tens and 3 ones. Taking away 10 means removing 1 ten, so 7 tens - 1 ten = 6 tens. The ones stay as 3. Step 4: 73 - 10 = 63. Aroha has 63 building blocks left.

  3. Emma has 12 crayons in her box. She finds 10 more crayons under her desk. How many crayons does Emma have now? Answer: 22 Solution: Emma starts with 12 crayons She finds 10 more crayons Add the crayons together: 12 + 10 12 + 10 = 22 Emma has 22 crayons now.
    Full step-by-step solution

    Step 1: Emma starts with 12 crayons Step 2: She finds 10 more crayons Step 3: Add the crayons together: 12 + 10 Step 4: 12 + 10 = 22 Emma has 22 crayons now.

  4. Aroha is reading a book that has 83 pages. She has already read 73 pages. How many more pages does she need to read to finish the book? Answer: 10 Solution: The book has 83 pages total. Aroha has read 73 pages. To find how many pages are left, subtract: 83 - 73.
    Full step-by-step solution

    Step 1: The book has 83 pages total. Step 2: Aroha has read 73 pages. Step 3: To find how many pages are left, subtract: 83 - 73. Step 4: 83 - 73 = 10. Step 5: Aroha needs to read 10 more pages. Final answer: 10

  5. Tane has 34 building blocks. His sister gives him 10 more blocks. How many building blocks does Tane have now? Answer: 44 Solution: Tane starts with 34 building blocks. Step 2: His sister gives him 10 more blocks. Step 3: Add the blocks together: 34 + 10.
    Full step-by-step solution

    Step 1: Tane starts with 34 building blocks. Step 2: His sister gives him 10 more blocks. Step 3: Add the blocks together: 34 + 10. Step 4: 34 has 3 tens and 4 ones. Adding 10 means adding 1 more ten, so 3 tens + 1 ten = 4 tens. The ones digit stays as 4. Step 5: 34 + 10 = 44. Tane has 44 building blocks now.

  6. 3 + 10 = ? Answer: 13 Solution: 3 + 10 = 13. The tens digit increases from 0 to 1.
  7. A farmer has 15 apples in a basket. If he picks 10 more apples from his tree, how many apples does he have now? Answer: 25 Solution: The farmer starts with 15 apples in the basket. He picks 10 more apples from his tree. This means we need to add these 10 apples to the 15 apples he already has.
    Full step-by-step solution

    Step 1: The farmer starts with 15 apples in the basket. Step 2: He picks 10 more apples from his tree. This means we need to add these 10 apples to the 15 apples he already has. Step 3: Perform the addition: 15 + 10. Step 4: Calculate 15 + 10. First, add the ones place: 5 + 0 = 5. Then, add the tens place: 1 + 1 = 2. So, 15 + 10 = 25. Step 5: Therefore, the farmer now has 25 apples in total. Final Answer: 25

  8. A baker had 14 cookies on a tray. She baked 10 more cookies. How many cookies are on the tray now? Answer: 24 Solution: Start with the number of cookies the baker had: 14 Add the number of new cookies she baked: 10 Combine the numbers: 14 + 10 = 24 The total number of cookies on the tray is 24.
    Full step-by-step solution

    Step 1: Start with the number of cookies the baker had: 14 Step 2: Add the number of new cookies she baked: 10 Step 3: Combine the numbers: 14 + 10 = 24 Step 4: The total number of cookies on the tray is 24.