Lesson 5 Expanded Form of Numbers

    • Let’s represent three-digit numbers as a sum of the value of each digit.

Warm-up True or False: Value of Digits

Decide if each statement is true or false. Be prepared to explain your reasoning.

Activity 1 Expressions and Three-digit Numbers

Problem 1

Andre has 3 hundreds. Tyler has 5 tens. Mai has 7 ones. They want to represent the amount they have using an equation.

Base-ten diagrams. 3 hundreds. 5 tens. 7 ones.

  1. Write an expression to represent the sum of their values.

    + +

  2. Write the total value as a three-digit number:

Problem 2

Write each number as the sum of hundreds, tens, and ones, and as a three-digit number.

  1. Base-ten diagram. 1 hundred. 9 tens. 2 ones.

    Expanded form:

    Three-digit number:

  2. Base-ten diagrams. 2 hundreds. 3 tens. 8 ones.

    Expanded form:

    Three-digit number:

  3. Base-ten diagram. 3 hundreds. 1 ten. 6 ones.

    Expanded form:

    Three-digit number:

  4. Base-ten diagrams. 4 hundreds. 2 tens. 1 one.

    Expanded form:

    Three-digit number:

Activity 2 Make It and Expand It

Problem 1

Base-ten blocks and 3 number cubes.

Roll the number cubes.

Make the largest number possible.

  1. Write it as a three-digit number.

  2. Write it in expanded form.

Problem 2

Roll the number cubes.

Make the smallest number possible.

  1. Write it as a three-digit number.

  2. Write it in expanded form.

Problem 3

Roll the number cubes.

Using the same digits, make a number different from your partner’s.

  1. Write it in expanded form.

  2. Write it as a three-digit number.

Practice Problem

Problem 1

  1. Represent each sum as a three-digit number.

  2. Represent each number as the sum of hundreds, tens, and ones.

    • 823

    • 407