In this lesson plan, second-grade students further develop their understanding of place value by identifying what each numeral of a three-digit number stands for. The lesson takes one 45-minute class period. Supplies include:

- Regular notebook paper or a math journal
- Base 10 blocks or base 10 block stamps
- Notecards with the numerals 0 through 9 written on them

The object of this lesson is for students to understand what the three digits of a number mean in terms of ones, tens and hundreds and to be able to explain how they came up with answers to questions about larger and smaller numbers.

### Performance Standard Met

- Understand that the three digits of a three-digit number represent quantities of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones.

### Lesson Introduction

Write 706, 670, 760 and 607 on the board. Ask the students to write about these four numbers on a sheet of paper. Ask "Which of these numbers is largest? Which number is the smallest?"

### Step-by-Step Procedure

- Give students a few minutes to discuss their answers with a partner or a tablemate. Then, have students read aloud what they wrote on their papers and explain to the class how they figured out the larger or smaller numbers. Ask them to decide what two numbers are in the middle. After they have had a chance to discuss this question with a partner or with their table members, solicit answers from the class again.
- Discuss what the digits mean in each of these numbers and how their placement is vitally important to the number. The 6 in 607 is very different from the 6 in 706. You can highlight this to students by asking them if they would rather have the 6 quantity in money from the 607 or the 706.
- Model 706 on the board or on an overhead projector, and then have students draw 706 and other numbers with base 10 blocks or base 10 stamps. If neither of these materials is available, you can represent hundreds by using large squares, tens by drawing lines and ones by drawing small squares.
- After you do model 706 together, write the following numbers on the board and have students model them in order: 135, 318, 420, 864 and 900.

- As the students write, draw or stamp these on their papers, walk around the classroom to see how students are doing. If some finish all five numbers correctly, feel free to provide them with an alternate activity or send them to finish up another project while you focus on the students who are having trouble with the concept.
- To close out the lesson, give every child a notecard with one numeral on it. Call three students to the front of the class. For example, 7, 3 and 2 come to the front of the class. Have the students stand next to each other, and have a volunteer "read" the threesome. Students should say "Seven hundred thirty-two." Then ask students to tell you who is in the tens place, who is in the ones place, and who is in the hundreds place. Repeat until the class period is over.

### Homework

Ask students to draw five three-digit numbers of their choice using squares for hundreds, lines for tens, and small squares for ones.

### Evaluation

As you are walking around the class, take anecdotal notes on the students who are struggling with this concept. Make some time later in the week to meet with them in small groups or—if there are several of them—reteach the lesson at a later date.