# Measurement

Students explore measurement using kilograms, grams, liters, milliliters, and intervals of time in minutes.

## Unit Summary

In Unit 7, students solve problems involving measurement and estimation of intervals of time, liquid volumes, and masses of objects. The unit, while major work itself, also “support[s] the Grade 3 emphasis on multiplication and the mathematical practices of making sense of problems (MP.1) and representing them with equations, drawings, or diagrams (MP.4)” (GM Progression, p. 18).

Students begin by building on their understanding of telling time to the nearest five minutes from Grade 2 (2.MD.7) to tell and write time to the nearest minute using analog and digital clocks (3.MD.1). Students see that an analog clock is a portion of the number line shaped into a circle. Just as students used a number line to represent sums and differences in Grade 2 (2.MD.6), students use the number line to represent addition and subtraction problems involving elapsed time in minutes and durations of time (3.MD.1).

Building on the estimation skills with length gained in Grade 2 (2.MD.3), students in Grade 3 use the metric units of kilograms, grams, liters, and milliliters to estimate the masses and liquid volumes of familiar objects (3.MD.2). Students also measure objects in those units, reading the measurement scales on analog tools such as beakers. Finally, just as students solved word problems involving lengths in Grade 2 (2.MD.5), students solve word problems involving masses or volumes given in the same metric units (3.MD.2).

Students will rely on the work of this unit to convert from a larger unit to a smaller unit in Grade 4 (4.MD.1) and from a smaller unit to a larger one in Grade 5 (5.MD.1), as well as to solve multi-step word problems involving intervals of time, liquid volumes, and masses of objects, including problems involving simple fractions or decimals (4.MD.2, 5.MD.1). Beyond the direct connections to Grade 5 Common Core State Standards, “measurement is central to mathematics, to other areas of mathematics (e.g., laying a sensory and conceptual foundation for arithmetic with fractions), to other subject matter domains, especially science, and to activities in everyday life. For these reasons, measurement is a core component of the mathematics curriculum” (GM Progression, p. 1).

Pacing: 15 instructional days (12 lessons, 2 flex days, 1 assessment day)

For guidance on adjusting the pacing for the 2020-2021 school year due to school closures, see our 3rd Grade Scope and Sequence Recommended Adjustments. • Expanded Assessment Package
• Problem Sets for Each Lesson
• Student Handout Editor
• Vocabulary Package

## Assessment

This assessment accompanies Unit 7 and should be given on the suggested assessment day or after completing the unit.

## Unit Prep

### Intellectual Prep

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#### Intellectual Prep for All Units

• Read and annotate “Unit Summary” and “Essential Understandings” portion of the unit plan.
• Do all the Target Tasks and annotate them with the “Unit Summary” and “Essential Understandings” in mind.
• Take the unit assessment.

### Essential Understandings

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• “An open number line can be a useful tool to help students visualize and organize [information regarding elapsed time situations]. In order to do this effectively, students must be able to decompose time into strategic chunks” (Dajuana's Homework, Illustrative Mathematics).
• Mass and liquid volume measurements are often shown on a measurement scale that is similar to a number line.

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gram

millimeter

kilogram

liquid volume

liter

mass

### Unit Materials, Representations and Tools

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• Analog scale (that measures in grams and kilograms, 1 per teacher)
• Balance scale (1 per group of students)
• Beakers (100 mL and 1 L, 1 of each per teacher)
• Containers of various capacities, including containers close to the benchmark capacities of 1 milliliter and 1 liter
• Containers with the capacity of 1 quart, 1 pint, .5 liter, and quarter teaspoon
• Demonstration analog clock (1 per teacher)
• Digital scale (1 per group of students)
• Empty 1-liter bottle with top cut off (1 per group of students)
• Permanent marker
• Plastic cups that can hold at least 100 mL (1 per group of students)
• Scissors, thumbtacks, rulers, and textbooks (1 each per group of students)
• Snap cubes (or other nonstandard unit to be used to measure mass)
• Objects of various masses, including objects close to the benchmark masses of 1 gram, 10 grams, 100 grams, and 1 kilogram (suggested: paper clips, dictionaries, coins, safety pins)
• Water

For notes on possible modifications to materials related to mass, see Lessons 7 and 8. For notes on possible modifications to materials related to volume, see Lessons 10 and 11.

## Common Core Standards

Key: Major Cluster Supporting Cluster Additional Cluster

### Core Standards

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##### Measurement and Data
• 3.MD.A.1 — Tell and write time to the nearest minute and measure time intervals in minutes. Solve word problems involving addition and subtraction of time intervals in minutes, e.g., by representing the problem on a number line diagram.

• 3.MD.A.2 — Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l). Add, subtract, multiply, or divide to solve one-step word problems involving masses or volumes that are given in the same units, e.g., by using drawings (such as a beaker with a measurement scale) to represent the problem. Excludes multiplicative comparison problems (problems involving notions of "times as much"; Excludes compound units such as cm³ and finding the geometric volume of a container.

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• 2.MD.A.1

• 2.MD.A.3

• 2.MD.B.6

• 2.MD.C.7

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• 4.MD.A.1

• 4.MD.A.2

### Standards for Mathematical Practice

• CCSS.MATH.PRACTICE.MP1 — Make sense of problems and persevere in solving them.

• CCSS.MATH.PRACTICE.MP2 — Reason abstractly and quantitatively.

• CCSS.MATH.PRACTICE.MP3 — Construct viable arguments and critique the reasoning of others.

• CCSS.MATH.PRACTICE.MP4 — Model with mathematics.

• CCSS.MATH.PRACTICE.MP5 — Use appropriate tools strategically.

• CCSS.MATH.PRACTICE.MP6 — Attend to precision.

• CCSS.MATH.PRACTICE.MP7 — Look for and make use of structure.

• CCSS.MATH.PRACTICE.MP8 — Look for and express regularity in repeated reasoning.