# Lesson 2

Anchoring Units of Measurement

### Lesson Narrative

This lesson is optional. Students have worked with standard units of length since grade 2, and standard units of volume and mass since grade 3. This lesson is designed to anchor students’ perception of standard units of length, volume, weight, and mass with a collection of familiar objects that they can refer to in later lessons in preparation for using ratio reasoning to convert measurement units.

The main task of this lesson is a card-sorting activity in which students match common objects with their closest unit of length, volume, mass, or weight to establish anchor quantities for each unit of measurement. Since this lesson reinforces standards from previous grade levels instead of introducing grade 6 standards, if you believe that your students already have a firm grasp of these units of measurement, you may choose to skip this lesson.

### Learning Goals

Teacher Facing

• Compare (orally) the relative size of different units of measure for one attribute, i.e., length, volume, weight or mass.
• Comprehend the approximate size of 1 “inch,” “foot,” “yard,” “mile,” “millimeter,” “centimeter,” “meter,” “kilometer,” “ounce,” “pound,” “ton,” “gram,” “kilogram,” “cup,” “quart,” “gallon,” “milliliter,” and “liter.”
• Identify which unit is closest to the length, volume, weight, or mass of a given object, and explain (orally) the reasoning.

### Student Facing

Let’s see how big different things are.

### Required Preparation

For the warm-up activity, each group of 2 students needs scissors and more string than necessary for their assigned unit of length. To distribute the string without wasting too much or giving away the actual lengths, consider dividing one ball of string ahead of time into equal spools, enough for every group to get one. The spools can then be reused class after class. Rotate the spools between groups assigned shorter and longer lengths, so that one spool does not run out long before the others. Only one of each of the rulers, meter sticks, and yardsticks is needed for demonstration purposes.

For the Measurements Card Sort activity, prepare 1 copy of the blackline master for each group of 4–6 students. These slips can be reused from one class to the next. If possible, copy each complete set on a different color of paper, so that a stray card can quickly be put back.

Also for the Measurements Card Sort activity, prepare several examples of real objects depicted on the cards, so the students can see them at actual size, especially any objects on the cards that may be unfamiliar to students. A real quart-sized bottle is an especially crucial example to have.

### Student Facing

• I can name common objects that are about as long as 1 inch, foot, yard, mile, millimeter, centimeter, meter, or kilometer.
• I can name common objects that weigh about 1 ounce, pound, ton, gram, or kilogram, or that hold about 1 cup, quart, gallon, milliliter, or liter.
• When I read or hear a unit of measurement, I know whether it is used to measure length, weight, or volume.

Building On

Building Towards