Learn on PengiIllustrative Mathematics, Grade 5Chapter 6: Place Value Patterns and Decimal Operations

Lesson 1: Place Value Patterns and Powers of 10

In this Grade 5 lesson from Illustrative Mathematics Chapter 6, students explore place value patterns by examining how each digit in a decimal represents ten times as much as the digit to its right and one tenth as much as the digit to its left. Students practice expressing these multiplicative relationships using multiplication and division equations with decimals and whole numbers, such as 6 × 0.1 = 0.6 and 600 ÷ 100 = 6. This lesson builds the foundation for working with powers of 10 and measurement conversions covered throughout the chapter.

Section 1

Place Value

Property

Each place represents 10 times the place just to the right. A number is a sequence of digits, and its value is the sum of each digit multiplied by its place value (a power of ten). For example:

3041=3×1000+0×100+4×10+13041 = 3 \times 1000 + 0 \times 100 + 4 \times 10 + 1

This can also be written using exponents:

3041=3×103+0×102+4×101+1×1003041 = 3 \times 10^3 + 0 \times 10^2 + 4 \times 10^1 + 1 \times 10^0

Examples

  • The number 5,281 in expanded form is 5×1000+2×100+8×10+15 \times 1000 + 2 \times 100 + 8 \times 10 + 1.
  • The number 709 shows the importance of zero as a placeholder. It is 7×100+0×10+97 \times 100 + 0 \times 10 + 9.
  • A larger number like 4,600 is written as 4×1000+6×100+0×10+0×14 \times 1000 + 6 \times 100 + 0 \times 10 + 0 \times 1.

Explanation

Place value is like a secret code where a digit's position tells you its real worth. A 7 in the tens place is 70, but in the hundreds place, it's 700! This system lets us write any number, big or small.

Section 2

Conceptual Model: Relating Adjacent Place Value Units

Property

Each place value unit is 10 times greater than the unit to its immediate right.
This creates a multiplicative relationship where one of a larger unit can be decomposed into ten of the next smaller unit.

1 one=10 tenths1 \text{ one} = 10 \text{ tenths}
1 tenth=10 hundredths1 \text{ tenth} = 10 \text{ hundredths}
1 one=100 hundredths1 \text{ one} = 100 \text{ hundredths}

Examples

Section 3

Concept: The Placeholder Zero in Multiplication

Property

Each place value is 10 times greater than the place value to its immediate right.
Therefore, multiplying a number by 10 shifts each of its digits one place to the left, increasing the number's total value by a factor of 10.

Examples

Book overview

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

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Chapter 6: Place Value Patterns and Decimal Operations

  1. Lesson 1Current

    Lesson 1: Place Value Patterns and Powers of 10

  2. Lesson 2

    Lesson 2: Metric Conversion with Powers of Ten

  3. Lesson 3

    Lesson 3: Multi-step Conversion Problems: Metric Units

  4. Lesson 4

    Lesson 4: Multi-step Conversion Problems: Customary Length

  5. Lesson 5

    Lesson 5: Add and Subtract Fractions with Equivalent Expressions

  6. Lesson 6

    Lesson 6: Subtract Fractions: Multiple Strategies

  7. Lesson 7

    Lesson 7: Solve Problems

  8. Lesson 8

    Lesson 8: Put It All Together: Add and Subtract Fractions

  9. Lesson 9

    Lesson 9: Representing Fractions on a Line Plot

  10. Lesson 10

    Lesson 10: Problem Solving with Line Plots

  11. Lesson 11

    Lesson 11: Compare Products Using Diagrams

  12. Lesson 12

    Lesson 12: Compare Without Multiplying

  13. Lesson 13

    Lesson 13: Compare to 1

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Place Value

Property

Each place represents 10 times the place just to the right. A number is a sequence of digits, and its value is the sum of each digit multiplied by its place value (a power of ten). For example:

3041=3×1000+0×100+4×10+13041 = 3 \times 1000 + 0 \times 100 + 4 \times 10 + 1

This can also be written using exponents:

3041=3×103+0×102+4×101+1×1003041 = 3 \times 10^3 + 0 \times 10^2 + 4 \times 10^1 + 1 \times 10^0

Examples

  • The number 5,281 in expanded form is 5×1000+2×100+8×10+15 \times 1000 + 2 \times 100 + 8 \times 10 + 1.
  • The number 709 shows the importance of zero as a placeholder. It is 7×100+0×10+97 \times 100 + 0 \times 10 + 9.
  • A larger number like 4,600 is written as 4×1000+6×100+0×10+0×14 \times 1000 + 6 \times 100 + 0 \times 10 + 0 \times 1.

Explanation

Place value is like a secret code where a digit's position tells you its real worth. A 7 in the tens place is 70, but in the hundreds place, it's 700! This system lets us write any number, big or small.

Section 2

Conceptual Model: Relating Adjacent Place Value Units

Property

Each place value unit is 10 times greater than the unit to its immediate right.
This creates a multiplicative relationship where one of a larger unit can be decomposed into ten of the next smaller unit.

1 one=10 tenths1 \text{ one} = 10 \text{ tenths}
1 tenth=10 hundredths1 \text{ tenth} = 10 \text{ hundredths}
1 one=100 hundredths1 \text{ one} = 100 \text{ hundredths}

Examples

Section 3

Concept: The Placeholder Zero in Multiplication

Property

Each place value is 10 times greater than the place value to its immediate right.
Therefore, multiplying a number by 10 shifts each of its digits one place to the left, increasing the number's total value by a factor of 10.

Examples

Book overview

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

Continue this chapter

Chapter 6: Place Value Patterns and Decimal Operations

  1. Lesson 1Current

    Lesson 1: Place Value Patterns and Powers of 10

  2. Lesson 2

    Lesson 2: Metric Conversion with Powers of Ten

  3. Lesson 3

    Lesson 3: Multi-step Conversion Problems: Metric Units

  4. Lesson 4

    Lesson 4: Multi-step Conversion Problems: Customary Length

  5. Lesson 5

    Lesson 5: Add and Subtract Fractions with Equivalent Expressions

  6. Lesson 6

    Lesson 6: Subtract Fractions: Multiple Strategies

  7. Lesson 7

    Lesson 7: Solve Problems

  8. Lesson 8

    Lesson 8: Put It All Together: Add and Subtract Fractions

  9. Lesson 9

    Lesson 9: Representing Fractions on a Line Plot

  10. Lesson 10

    Lesson 10: Problem Solving with Line Plots

  11. Lesson 11

    Lesson 11: Compare Products Using Diagrams

  12. Lesson 12

    Lesson 12: Compare Without Multiplying

  13. Lesson 13

    Lesson 13: Compare to 1