In this lesson, students apply the general procedure they just learned for solving \(px=q\) in order to define what \(\frac ab\) means when \(a\) and \(b\) are not whole numbers. Up until now, students have likely only seen a fraction bar separating two whole numbers. This is because before grade 6, they couldn't divide arbitrary rational numbers. Now an expression like \(\frac{2.5}{8.9}\) or \(\frac{\frac12}{\frac35}\) can be welldefined. But the definition is not the same as what they learned for, for example, \(\frac25\) in grade 3, where they learned that \(\frac25\) is the number you get by partitioning the interval from 0 to 1 into 5 equal parts and then marking off 2 of the parts. That definition only works for whole numbers. However, in grade 5, students learned that \(2÷3=\frac23\), so in grade 6 it makes sense to define \(\frac{2.5}{8.9}\) as \(2.5÷8.9\).
Lesson overview
 5.1 Warmup: Recalling Ways of Solving (5 minutes)

5.2 Activity: Interpreting \(\frac{a}{b}\) (15 minutes)
 Includes "Are you Ready for More?" extension problem
 5.3 Activity: Storytime Again (15 minutes)
 Lesson Synthesis
 5.4 Cooldown: Choosing Solutions (5 minutes)
Learning goals:
 Comprehend that the notation \(\frac{a}{b}\) can be used to represent division generally, and the numerator and denominator can include fractions, decimals, or variables.
 Describe (orally) a situation that could be represented by a given equation of the form \(x+p=q\) or \(px=q\).
 Express division as a fraction (in writing) when solving equations of the form \(px=q\).
Learning goals (student facing):
 Let's investigate what a fraction means when the numerator and denominator are not whole numbers.
Learning targets (student facing):
 I understand the meaning of a fraction made up of fractions or decimals, like \(\frac{2.1}{0.07}\) or \(\frac{\frac45}{\frac32}\).
 When I see an equation, I can make up a story that the equation might represent, explain what the variable represents in the story, and solve the equation.
Glossary:
 Access the complete Grade 6 glossary.
Standards:
 This lesson builds on the standards:CCSS.6.NS.A.1MS.6.NS.1CCSS.6.NS.B.3MS.6.NS.3
IM 6–8 Math was originally developed by Open Up Resources and authored by Illustrative Mathematics, and is copyright 20172019 by Open Up Resources. It is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). OUR's 6–8 Math Curriculum is available at https://openupresources.org/mathcurriculum/.
Adaptations and updates to IM 6–8 Math are copyright 2019 by Illustrative Mathematics, and are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).
Adaptations to add additional English language learner supports are copyright 2019 by Open Up Resources, and are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).
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