Lesson 7

Non-unit Fractions on the Number Line

Warm-up: Choral Count: One-fourths (10 minutes)

Narrative

The purpose of this Choral Count is to invite students to practice counting by \(\frac{1}{4}\) and notice patterns in the count. These understandings help students develop fluency and will be helpful later in this lesson when students will need to be able to locate fractions on the number line using their knowledge of unit fractions. Save the recorded count to compare to a count in an upcoming lesson.

Launch

  • “Count by \(\frac{1}{4}\), starting at \(\frac{1}{4}\).”
  • Record as students count. Record 4 fractions in each row, then start a new row. There will be 4 rows.
  • Stop counting and recording at \(\frac{16}{4}\).

Activity

  • “What patterns do you see?” (The bottom part of the fraction never changes. The top part of the fraction is increasing by 1. The rows end at counts of four in the top like 4, 8, 12, 16.)
  • 1–2 minutes: quiet think time
  • Record responses.

Student Response

For access, consult one of our IM Certified Partners.

Activity Synthesis

  • “How is counting by fractions the same as counting by whole numbers? How is it different?” (The top part of the fraction is just like counting by whole numbers, going up one. The bottom part is different because it doesn’t change.)
  • Consider asking:
    • “Who can restate the pattern in different words?”
    • “Does anyone want to add an observation on why that pattern is happening here?”
    • “Do you agree or disagree? Why?”
  • “This is a place where it’s helpful to talk about the top part of the fraction and the bottom part of the fraction. We have words for those parts. The bottom part of a fraction is called the denominator. It tells how many equal parts the whole was partitioned into. The top part of a fraction is called the numerator. It tells how many of the equal parts are being described. Look for places in today's lesson where that terminology might help you explain your reasoning.”
  • Display the terms “denominator” and “numerator” and their definitions, and keep displayed throughout the lesson.

Activity 1: Number Line Scoot (15 minutes)

Narrative

The purpose of this activity is for students to practice identifying fractional intervals along a number line. This is Stage 2 of the center activity, Number Line Scoot. This activity encourages students to count by the number of intervals (the numerator). Students have to land exactly on the last tick mark, which represents 4, to encourage them to move along different number lines. While this activity does not focus on equivalence, it gives students exposure to this idea before they work more formally with it in the next section. In the synthesis, students relate counting on a number line marked off in whole numbers to their number lines marked off in fractional-sized intervals.

It may be helpful to play a few rounds with the whole class to be sure students are clear on the rules of the game. Keep the number line game boards for center use.

Engagement: Develop Effort and Persistence. Check in and provide each group with feedback that encourages collaboration and community. For example, check in after the first round of Number Line Scoot.
Supports accessibility for: Attention, Social-Emotional Functioning

Required Materials

Materials to Gather

Materials to Copy

  • Number Line Scoot Stage 2 Gameboard
  • Number Line Scoot Stage 2 Directions

Required Preparation

  • Each group of 2 students needs a number cube.
  • Each student needs at least 5 base-ten cubes to use as game pieces.

Launch

  • Groups of 2
  • Give each group of 2 a gameboard, two recording sheets, a number cube, and at least 10 base-ten cubes.
  • “Now you will play a game where you move, by fractions, along different number lines. To start, each player places a small cube on zero on each number line. The goal of the game is to get as many small cubes as you can to the 4 on any of the number lines.”
  • Roll the number cube, demonstrate where to record the rolled number and move that fraction along one of the number lines.

Activity

  • 10 minutes: partner work time
  • As students work, monitor for students who count by the numerator once they have chosen a number line.

Activity Synthesis

  • Display a gameboard with a marker on \(\frac{3}{4}\).
  • “If I rolled a 4, and chose to move \(\frac{4}{4}\), how would you count the move?” (I would count 1, 2, 3, 4.)
  • “How did you know you have moved \(\frac{4}{4}\)?” (Because each space is \(\frac{1}{4}\), so I need to move 4 times.)
  • Display a number line marked with only 0, 1, 2, 3, 4.
  • “How is counting along this number line the same and different than counting along your number lines?” (On the whole number one each space is 1 so we just count 1, 2, 3, 4. On our number lines we still count the jumps, but now each space is smaller than 1 so we need the denominator to tell us the size of each space.)

Activity 2: Fractions on the Number Line (10 minutes)

Narrative

The purpose of this activity is for students to locate a variety of fractions on the number line. Students are given a fraction less than 1 and greater than 1 with the same denominator to locate on each number line. The activity synthesis focuses on counting the number of unit fractions in a fraction to locate it on a number line and how to determine whether fractions are less than 1 or greater than 1. As they locate the fractions on the number lines, students strengthen their understanding of the meaning of the numerator and denominator of a fraction (MP6).

MLR8 Discussion Supports. Synthesis: Some students may benefit from the opportunity to rehearse what they will say with a partner before they share with the whole class.
Advances: Speaking

Launch

  • Groups of 2
  • Display the number line for fourths from Number Line Scoot.
  • “What do you know about \(\frac{3}{4}\) and \(\frac{6}{4}\)?” (They both have 4 on the bottom. Three is less than 4 and 6 is greater than 4. They are both numbers of fourths.)
  • Share and record responses.

Activity

  • “Work with your partner to locate the fractions on each number line and answer the questions about your work.”
  • 4–6 minutes: partner work time
  • Monitor for students who locate non-unit fractions on the number line by partitioning into equal parts of size \(\frac{1}{b}\) and count the number of those parts.

Student Facing

  1. Locate and label \(\frac{3}{4}\) and \(\frac{6}{4}\).

    Number line. 0 to 2 by ones. Evenly spaced tick marks. First tick mark, 0. Last tick mark, 2.
  2. Locate and label \(\frac{7}{8}\) and \(\frac{12}{8}\).

    Number line. Evenly spaced tick marks labeled zero, one, and two.
  3. Locate and label \(\frac{2}{3}\) and \(\frac{4}{3}\).

    Number line. 0 to 2 by ones. Evenly spaced tick marks. First tick mark, 0. Last tick mark, 2.
  4. Locate and label \(\frac{2}{6}\) and \(\frac{7}{6}\).

    Number line. 0 to 2 by ones. Evenly spaced tick marks. First tick mark, 0. Last tick mark, 2.
  5. How did you partition the number line when you were locating the numbers \(\frac{7}{8}\) and \(\frac{12}{8}\)? Explain your reasoning.
  6. What patterns did you notice in the fractions you located?

Student Response

For access, consult one of our IM Certified Partners.

Advancing Student Thinking

If students partition the interval from 0 to 2 into fourths instead of the interval from 0 to 1 (or a similar error with another fraction), consider asking:
  • “Tell me about how you found \(\frac{3}{4}\) on the number line?”
  • “How does the denominator help us know how to partition the number line?”

Activity Synthesis

  • “What patterns did you notice in the fractions you located?”
  • Consider asking:
    • “How do you know when a fraction is less than 1?”
    • “How do you know when a fraction is greater than 1?”
  • “How did counting by unit fractions help you locate the other fractions on the number line?” (I counted by \(\frac{1}{4}\) three times to find \(\frac{3}{4}\). I counted by \(\frac{1}{6}\) as I moved along the number line, like \(\frac{1}{6}\), \(\frac{2}{6}\), \(\frac{3}{6}\), \(\frac{4}{6}\), \(\frac{5}{6}\), \(\frac{6}{6}\), \(\frac{7}{6}\) to find \(\frac{7}{6}\).)

Activity 3: What’s the Fraction? (10 minutes)

Narrative

The purpose of this activity is for students to determine how a number line is partitioned and what fraction is marked on it with only 0, 1, and 2 labeled. Students partition and locate and mark, but don’t label, a fraction on a number line and then trade with a partner to determine the fraction their partner has marked. Remind students to mark, but not to label their partitions and their fraction, so that their partner only has the 0, 1, and 2 to use to determine what fraction is on their number line.

Launch

  • Groups of 2
  • “Complete the first part of the activity on your own. Partition the number line and mark, but don’t label, a fraction on the number line. Don’t tell your partner how you are partitioning or what number you are marking.”
  • 2 minutes: independent work time

Activity

  • “Now, trade number lines with your partner and answer the questions about their number line. When you are both finished, share your reasoning”
  • 1–2 minutes: independent work time
  • 1–2 minutes: partner work time

Student Facing

  1. Partition the number line into any number of equal-size parts. Locate and mark, but don’t label, a fraction of your choice.

    Number line. Evenly spaced tick marks labeled 0, 1, and 2.

  2. Trade number lines with a partner.

    1. How did your partner partition their number line?
    2. What number did your partner mark on their number line? Explain your reasoning.

If you have time, play the game again.

Number line. 0 to 2 by ones. Evenly spaced tick marks. First tick mark, 0. Last tick mark, 2.

Number line. Evenly spaced tick marks labeled 0, 1, and 2.

Students working together.

Student Response

For access, consult one of our IM Certified Partners.

Activity Synthesis

  • Display a number line partitioned by a student.
  • “Talk to your partner about what fraction is represented.”
  • Share and record responses.
  • Consider asking:
    • “How did you decide how to partition your number line and what fraction you’d put on your number line?”
    • “How did you decide how your partner’s number line was partitioned and decide what fraction was marked?”

Lesson Synthesis

Lesson Synthesis

“Today we located more fractions on the number line. In an earlier lesson, we learned how fractions are built from unit fractions. How do we see this on the number line?” (I counted the unit fractions, like 3 one-fourths, to get to \(\frac{3}{4}\). I partition the number line into unit fractions and then I can count parts up to the fraction I am locating.)

Draw or have students draw a number line with \(\frac{3}{4}\) marked, such as:

Number line.
Trace or have them trace through and count the 3 one-fourths to get to \(\frac{3}{4}\), such as:
Number line.

“Remember, when we are locating a fraction on the number line, it might be helpful to think about or show the 3 one-fourth parts, and then we mark and label the number \(\frac{3}{4}\) at the end of those parts. When we locate and label fractions, you don’t have to mark the length, you can just count the unit fractions and then mark and label the point at the end.”

Point to the location of each fraction on the number line and count: “\(\frac{1}{4}\), \(\frac{2}{4}\), \(\frac{3}{4}\).”

Cool-down: Where is $\frac{5}{3}$? (5 minutes)

Cool-Down

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