Fractions

Created by: Cheryl Carpenter [ccarpenter@reg8.net]

Region VIII ESC

January 2003

Objectives:

The student uses fraction names and symbols to describe fractional parts of whole objects or sets of objects.

The student is expected to construct concrete models of fractions TEK (3.2a)

The student is expected to compare fractional parts of whole objects in a problem situation using concrete models TEK (3.2b)

The student is expected to use fraction names and symbols to describe fractional parts of whole objects or sets of objects with denominators of 12 or less TEK (3.2c)

The student is expected to construct concrete models of equivalent fractions for fractional parts of whole objects TEK (3.2d)

C Layer

Day One - Given a whole, find a unit fraction (a fraction with a numerator of 1)

Teacher models using Cuisenaire rods to find rods that represent unit fractions.

If the brown rod is one, find a rod that would represent ¼. Explain how you know the rod equals ¼. (Example: It takes 4 red rods to equal the length of the brown rod. One of four equal parts is ¼. Therefore, one red rod equals ¼ of the brown rod.)

Orange = 1. Find ½. Find 1/5. Find 1/10.

Green = 1. 1/3 = __________________.

Orange + red = 1. Find ½, 1/6, ¼, 1/3.

Guided practice - student manipulates the Cuisenaire rods.

Assignment: Choose 1 from each set.

Set 1

Dark green = 1. Find ½, 1/3, 1/6

Purple = 1. Find ½, ¼

Brown = 1. find ¼, ½, 1/8

Set 2

Yellow = 1. 1/5 = ______________.

Blue = 1. 1/3 = ________________.

Green = 1 1/3 = ________________.

Set 3

Black + green = 1. Find ½, 1/5, 1/10

Purple + Purple = 1. Find ¼, ½, 1/8

Orange + Red = 1. Find ½, 1/6, ¼, 1/3

Day Two - Use unit fractions to build an understanding of non-unit fractions (a fraction with a numerator other than 1)

Teacher models using pattern blocks.

If the yellow hexagon is one, find pattern block(s) that would represent 1/6, 3/6, 2/6. Explain your reasoning. (Example: It takes 6 green triangles to equal the area of the yellow hexagon. One of six equal parts is 1/6. It takes 3 green triangles to equal the red trapezoid. Since we named one green triangle 1/6, 3 green triangles equal 3/6. Therefore, the red trapezoid equals 3/6. It takes 2 green triangles to equal the blue rhombus. One green triangle is 1/6 so 2 green triangles equal 2/6. Therefore, the rhombus equals 2/6.)

If yellow + red = 1, find 1/9, 4/9, 2/9

2 yellow hexagons = 1. Find 1/6, 2/6, 3/6, 5/6

Guided practice - student manipulates the blocks.

Choose 1 from each set.

Set 1

Red trapezoid = 1. Find 1/3,2/3

Yellow hexagon = 1. Find 1/6, 3/6, 2/6

Blue rhombus = 1. Find ½

Set 2

Yellow hexagon + blue rhombus = 1. Find 1/8, 2/8, 3/8, 6/8

Red trapezoid + blue rhombus = 1. Find 1/5, 2/5, 3/5

Yellow hexagon + red trapezoid = 1. Find 1/9, 4/9, 2/9

Set 3

2 red trapezoids = 1. Find 1/6, 2/6, 3/6, 6/6

2 blue rhombus = 1. Find ¼, 2/4, ¾

2 yellow hexagons = 1. Find 1/6, 2/6, 3/6, 5/6

Day Three - Given a unit fraction, identify the whole.

Teacher models using linking cubes. If 4 cubes = 1/3, what is 1? Explain how you know. (Example: It takes 3 of 3 equal parts to equal one. Since 4 cubes is 1/3, three sets of 4 cubes would be 12 cubes. So 12 cubes equal one.)

Guided practice - Student manipulates the cubes.

5 cubes = ½. What is 1?

2 cubes = ¼. What is 1?

3 cubes = 1/5. What is 1?

Teacher models using counters. If 2 counters = ¼, what is 1?

Guided practice - Student manipulates the cubes.

4 counters = 1/3. What is 1?

3 counters = ½. What is 1?

2 counters = 1/6 What is 1?

Choose 2 from each set.

Set 1

3 cubes = 1/6. What is 1?

2 cubes = 1/5. What is 1?

5 cubes = 1/2. What is 1?

Set 2

3 counters = 1/3. What is 1?

4 counters = 1/2. What is 1?

2 counters = 1/6. What is 1?

Day 4 - B layer

Choose 1

How many different combinations of whole to part and part to whole can be made with 12 crackers?

How many equal parts can a pizza be divided into? Using that number, find as many combinations of whole to part and part to whole as you can.

You have been given two chocolate bars. How much would each person get if you had 2 friends and you got equal parts? 3 friends? 4 friends? 5 friends?

Day 5 - A layer

Choose 1

How would a cook use fractions? How would a carpenter use fractions? Would they be more important for a cook or a carpenter? Why?

In a magazine or newspaper find as many fractions as possible. How are they used? Which one is the most important?