## Perfect Places!

### Judy Bryant

#### Description

This lesson will help students understand the role of the decimal point and the relationship between tenths, hundredths, and thousandths.

#### Objectives

The student uses place-value concepts of grouping based upon powers of ten (thousandths, hundredths, tenths, ones, tens, hundreds, thousands) within the decimal number system.

#### Materials

-Grid paper
-Vis-à-vis pens
-Teacher-made Guided Practice Activity Sheet (See attached file)
-Copy of teacher-made Rubric for each student (See attached file)

#### Preparations

1. Set up the overhead projector
2. Make an overhead transparency of the grid paper
3. Make enough copies of attached Guided Practice Activity Sheet for each student.
4. Make enough copies of the attached rubric for each student.

#### Procedures

1. Introduce vocabulary: decimal, decimal point, tenths' place, and hundredths' place.

2. Pass out rubric and explain.

3. Display the overhead transparency of grid paper.

4. Have the students examine the 10x10 grid. Ask: How many small boxes make up the whole grid? (Answer: 100)

5. Have a student come to the projector, count out a row (10 squares), and shade it. Ask: What does the shaded part represent? (Answer: One tenth of a whole)

6. Ask students to explain ways to read and to write this decimal. (Answer: One-tenth, 0.1, or 1/10). The first place to the right of the decimal point is the tenths' place.

7. Have a second student come to the projector and shade in only one square of the grid. Ask: What does the shaded part represent? (Answer: One hundredth) What are the ways to read and write this decimal? (Answer: One hundredth, 0.01, or 1/100) The second place to the right of the decimal point is the hundredths' place.

9. Explain that one tenth (0.1) and ten hundredths (0.10) have the same value. Have a student come to the overhead and shade both values to illustrate that they are the same. Ask: If the first place to the right of the decimal is called the tenths' place and the second place to the right of the decimal is called the hundredths' place, what do you think the third place to the right of the decimal point is called? (Answer: Thousandths)

10. Ask students to name instances when it’s important to calculate and to record numbers less than 1. (Possible answers: Measurements, time, money) Use instances from life to show the class how each of the following decimals is written and read. (Example: Irene’s ice cream cost \$1.15.)

a. Compare 0.11 and 0.12- In the tenths' place, the digits are the same. Look at the hundredths. 2 is greater than 1, so 0.12>0.11.
b. Compare 0.02 and 0.120– 1 is greater than 0 in the tenths' place so 0.120>0.02.
c. Compare 2.17 and 0.99.– The ones are different. Since 2 is greater than 0, 2.17>0.99.

11. Remind students that when there are non-zero digits on both sides of the decimal point, they should say the word [and] where they see the decimal point. For example 3.14 is read as three and 14 hundredths.

12. Use models on a 10x10 grid as necessary to guide the class in comparing decimals numbers using > and <.

13. Distribute the Guided Practice Activity Sheet and have the students work in pairs.

1. 0.1 (>) 0.01
2. 1.06 (>) 1.007
3. 0.2 (<) 0.22
4. 1.003 (>) 0.339
5. 0.13 (<) 0.31
6. 0.005 (<) 0.011
7. 0.51 (>) 0.509
8. 1.460 (<) 1.604
9. 0.999 (<) 1.000
10. 0.183 (>) 0.083

14. Teacher circulates, observes students working together, and answers any questions.

15. Teacher assesses the students using the rubric, gives feedback, and reteaches as needed.

#### Assessments

Reads and writes decimals using tenths, hundredths, and thousandths and compares decimals using greater-than and less-than.

Evidence:
Use the following three-point rubric to evaluate how well students did in class.

·Three points: Clearly understood and applied what they learned to understand the role of the decimal point and the relationship among tenths, hundredths, and thousandths.
·Two points: Partially understood and applied what they learned to understand the role of the decimal point and the relationship among tenths, hundredths, and thousandths.
·One point: Very little understanding and had difficulty applying what they learned to understand the role of the decimal point and the relationship among tenths, hundredths, and thousandths.