Standard

Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.

Student language:

• "I can compare the length of an object using two different units of measurement."

Explanation

About the Math, Learning Targets, and Rigor

This standard calls for students to measure an object using two units of different lengths.

Example

A student measures the length of their desk and finds that it is 3 feet and 36 inches.

Students should explore the idea that the number of units for length of the desk is greater in inches than in feet. This concept is referred to as the compensatory principle. They describe the relationship between the size of the measurement unit and the number of units needed to measure something. For instance, a student might say, “The longer the unit, the fewer I need.”

Important Tip

Insist that students always estimate lengths before they measure. Estimation helps them focus on the attribute to be measured, the length units, and the process. After they find measurements, have students discuss the estimates, their procedures for finding the measurements and the differences between their estimates and the measurements.

Resources

Videos

• Khan Academy
  • scroll to find 2.MD.2, click on a skill, watch videos on left side in each skill
• Learn Zillion

EngageNY Lessons

Extra Practice

• North Carolina Tasks
• Illustrative Math Tasks
• Howard County Tasks
  • Click on 2nd grade at bottom, then 2.MD.2
• Common Core Sheets

Released Assessment Questions

2.MD.2 Student Example

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