Beacon Lesson Plan Library

A Model Project

Cynthia Spear
Polk County Schools


This activity is a concrete way to introduce students to equivalent forms of fractions and decimals. The student constructs models to represent a fraction or a decimal.


The student uses concrete materials to model equivalent forms of whole numbers, fractions, and decimals.


-Base 10 blocks
-Overhead projector
-Overhead Models of Base 10 models (100, 10, 1)
-Base 10 Activity Sheet (see associated file)
-Chalk or white board


1. Gather Base 10 models to pass out at the beginning of the lesson.
2. Put Base 10 model pieces in groups for each student: 1 mat, 10 strips, 100 units.
3. Set up overhead projector and put overhead Base 10 models on the overhead.
4. Copy the Activity Sheet to be distributed after the lesson.


NOTE: This lesson addresses fractions and decimals only.

-Prior knowledge of the concept one, tenths, and hundredths using the Base 10 models is required before beginning this lesson.
-Prior knowledge of proper fractions (tenths and hundredths) is required for this lesson.
-Prior knowledge of the concept of “percent” is required for this lesson.

1. Distribute the Base 10 models. Each student receives a mat, 10 strips, and 100 units.

2. Introduce the lesson by asking the students what they know about the Base 10 models on their desks. Allow time for discovery and discussion with their classmates. Write responses on the board.

3. Write the word on the board and ask students if they see a familiar word inside the word “equivalent." Ask, "What do you think this word means?” Write their responses on the board.

4. Discuss with students that to be equivalent, numbers must be equal.

5. Have students use their models to find out how many strips it takes to cover the whole mat. Ask, “If the mat represents one whole and each strip is one-tenth of the whole mat, what can you say about how many tenths are equivalent to one whole?” Write the fraction for one-tenth on the board. Then write ten-tenths.

6. Ask students what they can conclude about how many hundredths are equivalent to one whole. Make sure they have grasped this concept before moving on to the next step. Write one-hundredth on the board. Then write one hundred one-hundredths on the board.

7. Explain to students that since fractions and decimals represent a part of the whole, they can represent the same amount.

8. Tell the students they are going to display models to show what fractions and decimals look like.

9. Have students show what the fraction 27/100 looks like. Circulate around the room to check on student models. Assist anyone who is having difficulty.

10. Draw the model of the students’ displays on the overhead. Use a square for the mats, a line for the strips, and a small square for the units.

11. Explain that .27 is 27 out of 100 which is the same as 27 out of 100 pennies. It could also be 27 points out of 100 points. Write the fraction and the decimal forms on the board.

12. Now have the students display what .27 looks like. Circulate again to assist students who may be having difficulty.

13. Draw the model of the students’ displays on the overhead. Have the students tell what they notice about the two illustrations. Illicit from the class that 27/100 and .27 equal the same amount. Point out the equivalent fraction and decimal written forms.

14. Practice setting up more models of equivalent fractions and percents. Write the fraction and decimal forms on the board. As the students display each number, circulate and do a formative assessment to determine who needs further help. Continue to assist those who are having difficulty.

15. After practice is completed tell students they will be doing the Activity Sheet (see associated file) for more practice.

16. Tell students they will be illustrating fractions and decimals using pictures of the Base 10 pieces as we have been doing in class.


Note: Only fractions and decimals which are tenths and hundredths are being assessed in this lesson.

As students practice, formatively assess them in making their models of given fractions and decimals using base ten manipulatives. Students should be given further assistance if needed during this time.

As a formative assessment, students will draw models of given fractions and decimals as they are presented on the Activity Sheet. Criteria for mastery is 80%. Further assistance should be given if needed.

Attached Files

Base Ten Activity     File Extension: pdf

Return to the Beacon Lesson Plan Library.