A girl smiles behind a colorful bake sale table with treats

Maya's Bake Sale Mystery

Maya is selling cookies at the school fair. How many will she have left at the end? Some problems take more than one step to solve!

4th Grade Math

Step 1: Find the Total

Maya bakes 6 trays of cookies. Each tray holds 8 cookies. Let's analyze the problem one step at a time. The array shows every cookie. What is the product of 6 × 8?

6 × 8 = 48. The array shows 6 rows with 8 cookies in each row. Maya has 48 cookies in all. But wait, that is only step one!

Step 2: Subtract What She Sold

Maya sells 29 cookies before lunch. Now we determine how many cookies are left. We can write an equation and let c stand for the unknown.

48 − 29 = c

48 − 29 = 19. Think: 48 − 20 = 28, then 28 − 9 = 19. Maya has 19 cookies left. So c = 19.

Step 3: Check Your Answer

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10

20

30

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50

Is 19 a reasonable answer? Round to check! On the number line, 48 is close to 50 and 29 is close to 30. What is 50 − 30?

50 − 30 = 20. Our estimate, 20, is very close to 19. That is strong evidence that 19 is a reasonable answer!

The Multi-Step Plan

          Four Steps to Success
        
          Step 1: Read and find the question.

          Step 2: Plan the steps you need.

          Step 3: Solve one step at a time. Use a letter for the unknown.

          Step 4: Check with rounding and estimation.

Maya's problem needed two steps: 6 × 8 = 48, then 48 − 29 = 19. One equation shows it all: 6 × 8 − 29 = c.

Watch Out! Don't Stop Too Soon

          A Common Mistake
        
          A student solved 6 × 8 = 48 and answered 48.

          But the question asked how many cookies were left!

          The real answer needed one more step: 48 − 29 = 19.

Always reread the question before you write your answer. Ask yourself: did I finish every step?

Practice: Theater Seats

A theater has 3 rows of 45 seats on the main floor. It has 28 more seats in the balcony. How many seats does the theater have in all?

First multiply: 3 × 45 = 135. Then add: 135 + 28 = 163 seats. Two steps, one answer!

Practice: Vans to Camp

130 students are going to camp. Each van holds 9 students. You must interpret the remainder to answer. How many vans do they need?

130 ÷ 9 gives a quotient of 14 with a remainder of 4. Those 4 students still need a ride, so they need 15 vans.

Practice: Match the Equation

Leo buys 4 packs of pencils. Each pack has 6 pencils. He gives 7 pencils to friends. Which equation shows p, the pencils Leo has left?

Multiply first: 4 × 6 = 24 pencils in all. Then subtract the pencils he gave away: 24 − 7 = 17. So p = 17.

Practice: Sharing the Money

Mia has $40. She spends $12 on a book. She splits the rest equally onto 4 gift cards. How much money goes on each card?

($40 − $12) ÷ 4 = ?

First subtract: $40 − $12 = $28. Then divide: $28 ÷ 4 = $7 on each gift card.

Practice: Estimate to Check

Kai solves 4 × 52 + 297 and gets 505. Round to check his work: 52 is about 50, and 297 is about 300. What is a good estimate?

4 × 50 = 200, and 200 + 300 = 500. The estimate, 500, is close to 505, so Kai's answer is reasonable.

Challenge: Three Steps!

A school orders 8 boxes of juice. Each box holds 24 packs. Then 3 classes each take 45 packs for a picnic. How many juice packs are left?

Step 1: 8 × 24 = 192 packs in all. Step 2: 3 × 45 = 135 packs taken. Step 3: 192 − 135 = 57 packs left.

When have you solved a real problem that took more than one step? How could rounding help you check your answer?

Great Work!

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product quotient remainder analyze interpret determine