Learn on PengienVision, Mathematics, Grade 4Chapter 5: Use Strategies and Properties to Divide by 1-Digit Numbers

Lesson 2: Mental Math: Estimate Quotients

In this Grade 4 enVision Mathematics lesson from Chapter 5, students learn how to estimate quotients using compatible numbers and multiplication when dividing 3-digit dividends by 1-digit numbers. Students practice replacing difficult numbers with nearby compatible numbers to make mental math easier, such as replacing 700 ÷ 9 with 720 ÷ 9 because 720 is divisible by 9. The lesson builds number sense by applying basic multiplication facts to check whether estimated quotients are reasonable in real-world contexts.

Section 1

Relating Division to Finding a Missing Factor

Property

Solving a division problem, such as A÷B=?A \div B = ?, is the same as finding the unknown factor in the related multiplication equation, B×?=AB \times ? = A.
The quotient of the division is the unknown factor.

Examples

Section 2

Choosing Compatible Numbers for Estimation

Property

Compatible numbers are numbers that are easy to compute mentally. When estimating quotients, replace the dividend with a nearby number that is a multiple of the divisor, which is often more effective than using standard rounding rules.

Examples

Book overview

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Chapter 5: Use Strategies and Properties to Divide by 1-Digit Numbers

  1. Lesson 1

    Lesson 1: Mental Math: Find Quotients

  2. Lesson 2Current

    Lesson 2: Mental Math: Estimate Quotients

  3. Lesson 3

    Lesson 3: Mental Math: Estimate Quotients for Greater Dividends

  4. Lesson 4

    Lesson 4: Interpret Remainders

  5. Lesson 5

    Lesson 5: Use Partial Quotients to Divide

  6. Lesson 6

    Lesson 6: Use Partial Quotients to Divide: Greater Dividends

  7. Lesson 7

    Lesson 7: Use Sharing to Divide

  8. Lesson 8

    Lesson 8: Continue Sharing to Divide

  9. Lesson 9

    Lesson 9: Choose a Strategy to Divide

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Relating Division to Finding a Missing Factor

Property

Solving a division problem, such as A÷B=?A \div B = ?, is the same as finding the unknown factor in the related multiplication equation, B×?=AB \times ? = A.
The quotient of the division is the unknown factor.

Examples

Section 2

Choosing Compatible Numbers for Estimation

Property

Compatible numbers are numbers that are easy to compute mentally. When estimating quotients, replace the dividend with a nearby number that is a multiple of the divisor, which is often more effective than using standard rounding rules.

Examples

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 5: Use Strategies and Properties to Divide by 1-Digit Numbers

  1. Lesson 1

    Lesson 1: Mental Math: Find Quotients

  2. Lesson 2Current

    Lesson 2: Mental Math: Estimate Quotients

  3. Lesson 3

    Lesson 3: Mental Math: Estimate Quotients for Greater Dividends

  4. Lesson 4

    Lesson 4: Interpret Remainders

  5. Lesson 5

    Lesson 5: Use Partial Quotients to Divide

  6. Lesson 6

    Lesson 6: Use Partial Quotients to Divide: Greater Dividends

  7. Lesson 7

    Lesson 7: Use Sharing to Divide

  8. Lesson 8

    Lesson 8: Continue Sharing to Divide

  9. Lesson 9

    Lesson 9: Choose a Strategy to Divide