1/2 1/4 1/8

Action Fractions

By Dena R. Hall

This lesson was created as a part of the SMART website and is hosted by the Illinois Institute of Technology

This lesson is intended for third grade, but can easily be adapted for lower or higher grades.  The time allotted for this lesson can be 1 to 2 weeks.

Objectives:

• # name the numerator and denominator in a fraction

• manipulate materials to show examples of equivalent  fractions

 Materials needed: construction paper, paper plates, crayons, plastic knives, oranges, paper towels, math textbook, math worksheets, games, software programs: Mighty Math Number Heroes, chalkboard, and colored chalk, manipulatives like:  Fraction Cubes, Fraction Stax, and Frog Pond Fractions (game which can be used like manipulatives.)

# Strategies:

1.    Pass out a sheet of  construction paper to students and tell them to fold the paper in half.  Explain to them that they have just divided a whole sheet of paper into two equal parts and that a fraction is a part of a whole.  Ask the students to take a crayon and trace the fold of their papers and color one-half or one part of their paper.  Write 1/2 on the chalkboard and say that the part of the paper they colored is called one-half and can be written as:  1/2.

2.    Ask the students to think of something that might be divided into halves.  Write those things on the chalkboard.  Hopefully, some of the following things will be named:  a sandwich, an orange, a candy bar, etc.  Tell the students that there are two words or terms that you want them to remember.  Write the words numerator and denominator on the chalkboard.  Have the students say the words. Tell them that the top number in a fraction is called the numerator, and the bottom number is called the denominator.  Further explain that the numerator tells how many parts are shaded, and that the denominator tells the total number of equal parts.

3.    Draw a circle on the chalkboard.  Divide it into halves, then fourths.  Ask a student to use a piece of colored chalk and color in two fourths.  Is two fourths the same as one half?  Let’s find out.

4.    Tell the students that they are going to work in pairs.  Give an orange and a plastic knife to each child.  Have them place the orange on the paper plate.  One student will cut the orange into two equal parts.  The other student will cut the halves of the orange in half so that there are four equal pieces.  Instruct the children to put the orange “back together”.  How many parts are there?  (The response should be “four”).  How many parts make up 1 whole orange?  (The response should be “four”).  Say, ¼ + ¼ + ¼ + ¼ = 4/4 or 1 whole.  Can anyone write a number sentence that shows that?

5.    Pass out two generic paper plates to each student.  Have them to fold one of the plates in half.  Trace the fold with a crayon.  Cut along the fold until the plate is cut into two equal parts.  Tell the students to label each part ½.  Have the students place each half onto the other plate.  Ask the students to describe what they notice.  Hopefully, they will respond by stating that two halves is the same as 1 whole, or two parts make up one whole, the parts fit inside the other plate.

6.    Next, have the students take one of the halves and fold it in half.  Trace the fold and cut along the fold.  Do the same with the other half. Label each of the four parts, ¼.  Place the fourths inside of the plate.  Ask the kids leading questions like:  Has anything changed?  Do the pieces fit inside the plate?  How many fourths make up I plate or 1 whole?  How many halves make up 1 whole?

7.   Tell the students to remove two of the fourths.  How many fourths are there on the whole (plate) now?  Hopefully, the students will respond by saying that there are two fourths, 2/4.  Explain that yes, there are two fourths on the plate and that those two fourths make up one-half (1/2) of the whole.  Therefore, two fourths is the same as one half.   We call these kinds of fractions, equivalent fractions. Ask if someone can think of a number sentence that says two fourths is the same as one-half.     ½ + ½ = 2/4

8.    Follow up activities in the Computer Lab using Mighty Math Number Heroes.

Assessment:

1.    Teacher observations.

Clipboard Cruising- teacher uses a clipboard with a rubric attached or a checklist and assesses students performing a "task" like using  the fraction cubes to show that 2/4 is the same as 1/2 .

2.    http://www.quia.com/jg/65839.html or
http://www.math.com/school/subject1/S1U4Quiz.html
Fraction Quiz. (80% mastery)

3.    Test on Fractions.  (80% mastery)

Resources:

http://funbrain.com/fract/index.html

http://www.visualfractions.com/IdentifySets/identify_sets.html

http://www.mathbuilder.com/

http://www.aaamath.com/fra16-fractions.html

http://www.mathleague.com/help/fractions/fractions.htm#whatisafraction

http://math.rice.edu/~lanius/Patterns/notes.html