Mental Math Strategies

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Mental Math Strategies · Grade 2 · Worksheet 1

1. Harper had 14 toy cars. Harper gave 11 cars to a friend. How many toy cars does Harper have now? Answer: 3 Solution: Start with 14 toy cars. Subtract 11 cars that were given away: 14 - 11 = 3.
   Full step-by-step solution

   Step 1: Start with 14 toy cars. Step 2: Subtract 11 cars that were given away: 14 - 11 = 3. The answer is 3.

2. A farmer has 36 apples and picks 24 more apples from his tree. How many apples does the farmer have in total? Answer: 60 Solution: The farmer starts with 36 apples. The farmer picks 24 more apples from his tree. This means we need to add these new apples to the ones he already has.
   Full step-by-step solution

   Step 1: The farmer starts with 36 apples. Step 2: The farmer picks 24 more apples from his tree. This means we need to add these new apples to the ones he already has. Step 3: To find the total number of apples, we perform the addition: 36 + 24. Step 4: Let's break down the addition. First, add the numbers in the ones place: 6 + 4 = 10. Write down the 0 in the ones place and carry over the 1 to the tens place. Step 5: Now, add the numbers in the tens place, including the carried-over 1: 3 + 2 + 1 = 6. So, the tens place is 6. Step 6: Combining the tens and ones places, we get 60. Therefore, the farmer has 60 apples in total.

3. Lily has 34 stickers. Lily's mom gives Lily 3 more stickers. How many stickers does Lily have now? Answer: 37 Solution: Start with 34 stickers. Add 3 more stickers: 34 + 3 = 37.
   Full step-by-step solution

   Step 1: Start with 34 stickers. Step 2: Add 3 more stickers: 34 + 3 = 37. The answer is 37.

4. A classroom has desks arranged in 7 rows with 8 desks in each row. How many desks are there in total? Answer: 56 Solution: There are 7 rows of desks. Each row has 8 desks. To find the total number of desks, multiply the number of rows by the number of desks in each row: 7 × 8.
   Full step-by-step solution

   Step 1: There are 7 rows of desks. Step 2: Each row has 8 desks. Step 3: To find the total number of desks, multiply the number of rows by the number of desks in each row: 7 × 8. Step 4: 7 × 8 = 56. The answer is 56.

5. A baker made 48 cookies and put them equally into 4 boxes. How many cookies are in each box? Answer: 12 Solution: The baker has 48 cookies total There are 4 boxes to put them in equally To find how many in each box, divide 48 by 4 48 ÷ 4 = 12 So each box gets 12 cookies The answer is 12.
   Full step-by-step solution

   Step 1: The baker has 48 cookies total Step 2: There are 4 boxes to put them in equally Step 3: To find how many in each box, divide 48 by 4 Step 4: 48 ÷ 4 = 12 Step 5: So each box gets 12 cookies The answer is 12.

6. Noah has 42 stickers in his collection. For his birthday, his aunt gives him 25 more stickers. How many stickers does Noah have now? Answer: 67 Solution: Noah starts with 42 stickers. He receives 25 more stickers. Add the two amounts together: 42 + 25 First, add the ones: 2 + 5 = 7 Then, add the tens: 40 + 20 = 60 Combine the results: 60 + 7 = 67 Noah now has 67 stickers.
   Full step-by-step solution

   Step 1: Noah starts with 42 stickers. Step 2: He receives 25 more stickers. Step 3: Add the two amounts together: 42 + 25 Step 4: First, add the ones: 2 + 5 = 7 Step 5: Then, add the tens: 40 + 20 = 60 Step 6: Combine the results: 60 + 7 = 67 Noah now has 67 stickers.

7. Emma has 38 crayons in her art box. Her teacher gives her 24 more crayons for a class project. How many crayons does Emma have now? Answer: 62 Solution: Start with Emma's original crayons: 38 Add the new crayons from her teacher: 24 Add the tens: 30 + 20 = 50 Add the ones: 8 + 4 = 12 Combine the tens and ones: 50 + 12 = 62 The answer is 62.
   Full step-by-step solution

   Step 1: Start with Emma's original crayons: 38 Step 2: Add the new crayons from her teacher: 24 Step 3: Add the tens: 30 + 20 = 50 Step 4: Add the ones: 8 + 4 = 12 Step 5: Combine the tens and ones: 50 + 12 = 62 The answer is 62.