Unit 5 Family Materials

In this unit, students extend their understanding of the base-ten system to include numbers to 1,000.

Section A: The Value of Three Digits

In this section, the unit of a hundred is introduced. Students begin by looking at the large square base-ten block, and its corresponding base-ten drawing, to visualize 100, and to establish that 1 hundred equals 10 tens, which equals 100 ones.

After students develop an understanding of a hundred as a unit, students learn that the digits in three-digit numbers represent amounts of hundreds, tens, and ones. Students read and write three-digit numbers in different forms, including using base-ten numerals, number names, and expanded form.

Students write expressions and equations based on the base-ten blocks and base-ten drawings that they see. They recognize that the value of the digits in a three-digit number is revealed when using the fewest number of blocks to represent the number.

For example, the picture shows 2 hundreds, 11 tens, and 12 ones. However, students recognize that they will need to exchange 10 of the ones for a ten and 10 of the tens for a hundred to find the value of their number. After doing so, they recognize that they have 3 hundreds, 2 tens, and 2 ones for a value of 322.

Section B: Compare and Order Numbers within 1000

In this section, students continue to deepen their understanding of numbers to 1,000 using place value understanding and the number line diagram. As students recall the structure of the number line from the previous unit, they use this structure and place value understanding to locate, compare, and order numbers on the number line.

As students locate or estimate the location of three-digit numbers on number lines, they demonstrate an understanding of the number’s relative distance from zero, as well as the place value of the digits. This understanding helps them to compare and order three-digit numbers. For example, to order numbers, students can first locate them on the number line. Then, the numbers will be in order from least to greatest as students look from left to right on the number line.

In addition to using the number line to compare three-digit numbers, students also use familiar place value representations such as base-ten blocks and base-ten diagrams. Students compare and order numbers and write the comparisons using the symbols, \(>\), \(<\), and \(=\).

Try it at home!

Near the end of the unit, ask your student to think about the number 593 and complete the following tasks:

• Write the number as a number name and in expanded form.
• Draw an amount of base-ten blocks that has the same value.
• Create a number line from 500 to 600 and place the number on a number line.
• Compare the number to 539 using either \(>\), \(<\), or \(=\).

Questions that may be helpful as they work:

• What pieces of information were helpful?
• Can you explain to me how you solved the problem?
• Could you have drawn a different amount of base-ten blocks?