Fraction Pattern Blocks

Author: Miko Uhuru

Lesson Plan:

Instructor: Miko Uhuru

(7th Grade Pre-algebra: Number Sense 1.2)

Purpose: Students will add fractions with like and unlike denominators.

Outcome: Students will demonstrate their ability to compare fractions, make equivalent fractions, and add fractions with the same denominator and different denominators using pattern blocks.

Introduction: Before distributing the pattern blocks, the teacher will say, “Fractions are used in a variety of settings: cooking, construction, computer graphics, sports, stock market, etc. Pattern blocks offer a visual and physical representation of fractions. You can see them and touch them. Today, you will be able to compare fractions, make equivalent fractions, and add fractions with like and unlike denominators using pattern blocks.”

The teacher will show the students the bag of pattern blocks and each size of the pattern block. The pattern blocks will be distributed to each pair of students. The teacher will inform the students about the appropriate use of pattern blocks. Afterwards, the teacher will say, “I would like for you to make an object from the pattern blocks. You will have about five minutes to do so quietly with your partner.”

Through: About five minutes later, using the document camera, demonstrate the subsequent sequence. Hand out construction paper and the Tasks 1, 2, and 3 to the pairs of students. “Now I want you to sort the pattern blocks, according to their size and color to make one hexagon. Notice that the shapes have common features: one whole; two halves; three thirds; and six sixths. Compare the individual blocks. Look at Task 1. Make a list and draw equivalent pattern blocks and unequal pattern blocks on the construction paper. You and your partner will work together. One of you will be the writer/artist. One of you will be the mathematician. Do your best to cooperate with one another.” Ask questions as needed. “As a class, we will discuss your results for Task 1 before we go on to Task 2.” Give them enough time to complete Task 1. Use your discretion (5 to 10 minutes).

During the discussion, the teacher models the comparison of pattern blocks that are equivalent and that are unequal. Use the whole hexagon as a template for measuring one whole: ½ = 3/6; 2/6 = 1/3; 4/6 = 2/3. Some unequal pattern blocks are 1/3 ≠ ½; 1/3 ≠ 1/6; 1/6 ≠ ½. The teacher asks questions as needed. The teacher will discuss why 1/3 is less than ½; 1/6 is less than 1/3 and ½; discuss other unequal values from the pattern blocks.

For Task 2, the teacher will model the addition of fractions using pattern blocks: ½ + ½ = 1. The teacher will use two, one-half, pattern blocks that equal one whole.

“When the denominators are unlike or different, attach the pattern blocks like a puzzle. Remember what a whole hexagon looks like?

2 halves equal one whole

3 thirds equal one whole

6 sixths equal one whole.”

“Work with me on this example. Let’s add 1/6 + 1/3. What shape do they form, or what is the value of the two blocks? {Model as a Think Aloud} After attaching the pattern blocks, you could see how their value is close to one half, less than one half, less than one whole, or more than one whole. You can also use the equivalent fractions you listed from Task 1: 1/3 = 2/6. Add 1/6 to 2/6 equals 3/6 or one half.”

“Let’s add 3/6 + 2/3.” Solicit responses from students to demonstrate how to find the sum using a variety of methods.

“You will have an opportunity to complete Task 2 with your partner on the construction paper.” Discuss the Task 2 problems with the students.

Beyond: Students will complete Task 3. Each student will have an opportunity to express their perspectives in writing. Discuss with the students the importance of finding the equivalent fractions for adding/subtracting with unlike denominators. The students could use the LCM to find the LCD. In the following chapter, the students will be adding/subtracting fractions without manipulatives and must have a general idea of how to master that math standard. Post student work samples on the bulletin board.