options: Counting & Cardinality: students learn to know number names and the count sequence, count to tell the number of objects, and compare numbers.

Number Systems and Quantity: students learn to understand the complex number system and reason quantitatively.

Functions: students learn to define, use, and evaluate functions to model relationships between quantities.

Ratios & Proportional Relationships: students learn to recognize, describe, represent, and reason with ratios, rates, proportional relationships, and percent.

Number & Operations - Fractions: students learn to understand fractions as numbers and may work with them using addition, subtraction, multiplication, and division.

Statistics & Probability: students learn to analyze and produce data distributions, and build understanding of univariate and bivariate data. They learn to interpret data, make statistical inferences, justify conclusions, understand rules of probability, and use probability to make decisions.

Geometry: students learn to classify geometric figures by their properties, and understand and compare the relationships between them. Students develop and use formulas to compute lengths, areas, and volumes, and they use transformations to generate new shapes and compare existing ones. Geometry can be studied with and without coordinates.

Measurement & Data: students learn to work with data and measure attributes such as time, money, length, area, and volume. They may learn to compare measurements to operations and convert between different units of measure.

Number & Operations in Base Ten: students learn to work with the base-ten system and build place value understanding.

Modeling: students learn to choose and use appropriate mathematics and statistics to analyze real-world empirical situations, improve decisions, and report on their conclusions and the reasoning behind them.

Operations & Algebra: students learn to solve problems using algebraic thinking and operations such as addition, subtraction, multiplication, and division. They may learn to identify and explain arithmetic patterns, evaluate or manipulate numerical expressions, and reason with equations and inequalities.
problem_activity: Narrative
In this activity, students see that they can find equivalent fractions by dividing the numerator and denominator by a common factor. They connect this strategy to the process of grouping unit fractions on a number line into larger equal-size parts. The result is a fewer number of parts, and smaller numbers for the numerator and denominator of equivalent fractions.
MLR8 Discussion Supports.
Synthesis: At the appropriate time, give students 2–3 minutes to make sure that everyone in their group can explain the strategies used in the given examples. Invite groups to rehearse what they will say when they share with the whole class.
Advances: Speaking, Conversing, Representing
Launch
Groups of 2
Activity
“Work with your partner to answer the first three problems.”
“Be prepared to explain how you think Andre’s and Kiran’s strategies are related.”
7–8 minutes: partner work time
“Take a few minutes to answer the last problem independently.”
2–3 minutes: independent work time for the last problem
Student Facing
Andre drew a number line and marked a point on it. Label the point with the fraction it represents.
[IMG]
To find other fractions that the point represents, Andre made copies of the number line. He drew darker marks on some of the existing tick marks.
Label the darker tick marks Andre made on each number line.
[IMG]
[IMG]
Kiran wrote the same fractions for the points but used a different strategy, as shown. Analyze his reasoning.
\(\frac{8 \ \div \ 4}{12 \ \div \ 4}=\frac{2}{3}\)
\(\frac{8 \ \div \ 2}{12 \ \div \ 2}=\frac{4}{6}\)
How do you think Andre’s and Kiran’s strategies are related?
Try using Kiran’s strategy to find one or more fractions that are equivalent to
\(\frac{10}{12}\)
and
\(\frac{18}{12}\)
.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
“What did Andre do with the number lines? How would it help him find equivalent fractions?” (Andre grouped the 12 parts into equal groups of different sizes—2s, 4s—to make bigger parts. Then, he counted the number of those new parts.)
“What did Kiran do? How is his strategy related to Andre’s?” (Kiran divided 12 by 4 and then by 2, similar to how Andre put 12 parts into groups of 4 and then of 2.)
“Notice that the equivalent fractions
\(\frac{2}{3}\)
and
\(\frac{4}{6}\)
both have smaller numbers for the numerator and denominator than the original fraction. Can you use Andre’s number line to show why this might be?” (The size of the parts are bigger, so there are fewer parts in 1 whole.)
If time permits, ask students:
“How many equivalent fractions can you find for
\(\frac{10}{12}\)
using Kiran’s way?” (One) “How many can you find for
\(\frac{18}{12}\)
?” (Three)
“What might be a reason that you could find more equivalent fractions for
\(\frac{18}{12}\)
than for
\(\frac{10}{12}\)
?” (18 and 12 have more factors in common than 10 and 12.)
“How would you show
\(\frac{9 \ \div \ 3}{12 \ \div \ 3}=\frac{3}{4}\)
on the number line?” (Put the original 12 parts into groups of 3 to get 4 parts, each being a fourth. Mark 3 of those 4 parts to show
\(\frac{3}{4}\)
.)


correct_option_index: 4