Lesson 12

Workshop: Problem Solving with Fractions

Est. Class Sessions: 2–3

Developing the Lesson

Part 1. Comparing and Ordering Fractions Game

Give each student a card with a fraction. Ask students to first represent their fractions with drawings using circles. Then ask them to locate the fraction on the number line. Encourage them to use the benchmarks on the number lines. See Figure 2 for an example card. Ask students to check their work with a partner.

Since the index cards have a range of fractions, give students fractions according to their abilities. Give students who are developing their fraction abilities benchmarks or fractions that can readily be represented with fraction circles. For other students, give them fractions that are a bit more challenging to represent, such as 6/13, 16/17, or 1/50.

Ask students who have benchmark fractions (0, 1/2, 1, 11/2, 2) to stand in the front of the class holding up their fraction cards. Students should spread out and stand in order from smallest to largest. Then ask those students who have fractions near or equal to the 1/2 benchmark to come stand near the benchmark and put themselves (their fractions) in order from smallest to largest. Ask students to share how they know they are in the correct order and how they figured out if their fraction was larger than 1/2 or smaller than 1/2. Ask students who are not standing to check and correct the order.

Repeat this process with the other benchmarks. Then ask the rest of the students to join the line in the correct order. Use the questions below to guide a discussion about how students know the fractions are in order from smallest to largest. See the Sample Dialog.

  • Who is holding the smallest fractions? How do you know?
  • Who is holding the largest fractions? How do you know?
  • Who is holding fractions close to 1/2? How do you know?
  • Who is holding fractions larger than 1 whole? How do you know?
  • Look at your neighbors. Are the fractions in order from smallest to largest?
  • Explain why you are sure the fractions are in order. You may want to use a picture or number line to help you.
  • If they are not in order, where do you think the fraction should be? Explain why.
  • Before we start the Workshop problems, let's think a little more about numerators and denominators. When you compare fractions that have the same numerators, how can you tell which is larger? (Compare the size of the denominators. For example, 2/4 is greater than 2/5 because fifths are smaller than fourths.)
  • When you compare fractions that have the same denominators, how can you tell which is larger? (Compare the numerators. For example, 4/5 is greater than 3/5.)
  • What can you say about fractions equal to 1/2 ?(The numerators are exactly half of the denominators and the denominators are twice the numerators.)
  • What can you say about fractions close to zero? (They have small numerators but much larger denominators.)
  • What can you say about fractions close to 1? (They have numerators that are almost the same as their denominators.)
  • What can you say about fractions equal to 1? (They have the same numerator and denominator.)
  • What can you say about fractions greater than 1? (They have numerators that are larger than their denominators.)

Teacher: Who is holding the smallest fractions? How do you know?

Nila: The five kids at the beginning of the line are all holding fractions close to 0. The pictures don't have much shaded and all the numbers on the number lines are right by 0.

Teacher: That's a good use of the tools, Nila. How do the numerators relate to the denominators?

Ming: One's a lot bigger than the others.

Teacher: Use the terms numerator and denominator in your answer, so that it is clear.

Ming: The numerator is a lot smaller than the denominator.

Teacher: That's much clearer. Which ones are equal to 0?

Ming: 0, 0/2, and 0/12. The ones with 0 in the numerator.

Teacher: Shannon, Frank, David, and Ming, you all had fractions with denominators of one. How did you decide how to order them? Which one is smallest?

Frank: First, we thought that the one with 100 in it would be biggest, but then we thought about splitting a pizza. We wouldn't want just 1 piece of a pizza divided into 100 pieces. So then we said the ones with the biggest denominators would have the smallest pieces, so the order is 1/100 then 1/12, 1/10, 1/8, and 1/6.

Teacher: Which of you are holding the largest fractions in the whole line? What patterns do you see in those fractions?

Tanya: We are at this end of the line. All our numerators are much larger than the denominators.

Teacher: Well said. Give me some examples.

Tanya: 11/6, 12/6, 12/4.

Teacher: Good choices, Tanya. Who is holding fractions equal to 1/2 or close to 1/2 ?

Jackie: John, Keenya, Jacob, Linda, and I are in the middle. Our numerators are either bigger or smaller than 1/2 the denominator.

Teacher: I see where you are going with that, but be more precise. Anything could be bigger or smaller than half the denominator.

Jackie: The numerators are like half of the denominators.

Teacher: All of them are half? Which ones are half?

Jackie: 6/12 and 50/100

Teacher: John, you are holding 5/12 . How did you know where to get in line?

John: 5/12 is like half. Because if you divide 12 in half, that's 6. And 5 is close to 6.

Teacher: In fact, 5 is less than 6. So is 5/12 more than or less than 1/2 ?

John: It's less than 1/2. That's why I am on this side of 6/12.

This game can be used regularly during transitions or at the end or start of a class to provide practice with comparing and ordering fractions. You can change or add to the deck of fraction cards you created to focus on a particular issue or to address a particular student need. Later, decimals and percentages can be added to the deck to emphasize the equivalent representations of numbers less than 1. For example, 75% is the same as 3/4 and 0.75.

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A sample card showing 9/12 in a drawing and on a number line
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