## The Weight of Things

This lesson introduces and provides practice with the measurable attributes of weight. It also gives an opportunity to assess student knowledge of and skill in using measurement of mass. This learning experience focuses students’ attention on the attributes of weight using hands-on activities and active learning.

Gather all students in a group and complete a KWL Recording Chart about weight.

This establishes what students know and are curious about knowing about weight. Use the guiding questions below to prompt students’ thinking about measurement knowledge and skills.

Show students two objects of similar size. Ask them to predict which object weighs more. Give individual students two objects (of different weight), one in each hand and ask the student to share which one weighs more and which one weighs less.

Encourage students to share how they determined which weighed
more and which weighed less. Guide them to use mathematical terms
connected with weight such as *heavier* and *lighter* and *more* or *less*.
Offer this opportunity to all students who wish to participate. Be sure
to have a large number of items available for students to hold and
weigh so that everyone has a turn. Blocks, cubes, cotton balls, links,
books, and vegetables work well.

After all students have “weighed” two objects using their hands, ask “What are some other ways to determine the weight of an object?” Record the students’ responses and post for future reference. Next introduce a variety of scales for weighing objects (see the i-Plan materials list for suggestions). Provide a demonstration on each type of scale and then focus on the rocker balance. Using several examples, demonstrate how to weigh objects using this scale and discuss with students how they can tell which object weighs more (that side goes down) and which object weighs less (that side goes up).

Divide the class into pairs and provide each set of students with a pan balance, several sets of objects to weigh, and the Heavier, Lighter Activity Sheet.

Heavier, Lighter Activity Sheet

Have students use the pan balance scales to weigh pairs of objects and record their findings on the sheet provided.

Younger students should record using pictures and older students using words. Encourage students to predict which object is heavier or lighter before actually placing it on the scale. As students engage in this activity, observe what students do and say and ask guiding questions to help them focus on the important mathematical ideas of this lesson.

- Objects for weighing (Be sure to include a wide variety of objects that vary not only in weight but size as well)
- Pan Balance
- Any type of scale to provide a variety of examples
- Heavier, Lighter Activity Sheet
- KWL Recording Chart Overhead
- What I Learned Activity Sheet (assessment option)

**Assessment Options**

- At this point, it is important to determine whether students understand weight as a measurable attribute of objects and whether they are able to measure the weight of objects using standard and nonstandard units of measurement. Observation of students’ using their hands as scales provides knowledge of their basic understanding of the concept of weight.
- Further data can be gathered about students’ understanding of weight and how to measure during the activity using the pan balance. The completed Heavier, Lighter Activity Sheet can show whether students mastered the objectives of the lesson.
- Use the Class Notes recording sheet to document specific data on individual students and the class as a whole. This information helps you report to parents and to make instructional decisions about related lessons as well as mathematics lessons on other topics.
- As a way of "wrapping up" the unit, students may reflect upon their experiences on the What I Learned Activity Sheet.

**Extension**

Tie several lessons together by measuring the height and weight of each student in your class. For younger students at this grade band, use yarn as a nonstandard tool for measuring their height, then label it with the student’s name and hang the yarn from an opening in the room. This visual display enables students to compare lengths that represent heights. Placing the yarn strips in serial order allows students to see the relationships among the lengths from shortest to tallest. This visual reference creates a concrete graph that the teacher can transfer to a pictorial representation to model a conventional representation of data. In addition, record the students’ weights on a chart and then create a class graph to compare the weights.

**Questions for Students**

1. What is weight?

[Students may refer to weight as "how heavy" something feels. Accept reasonable responses.]

2. In what ways can we determine how much an object weighs?

[Use a pan balance, scale, etc.]

3. Why is it important to know how much things weigh? How do we use weight at school? How do you use measures of weight at home? How do your parents use measures of weight at work?

[Student responses may vary.]

4. What are words we use to describe how much an object weighs?

[Heavier, lighter.]

5. Does the size of an object always determine how much it weighs? Give examples of small objects that weigh a lot. Give examples of large objects that do not weigh a lot.

[No; student explanations may vary.]

**Teacher Reflection**

- Is there literature to support teaching weight?
- Which students met all the objectives of the lesson? Which students did not meet the objectives of the lesson?
- What adjustments could be made in future lessons to better teach this concept? Which management strategies worked well? What management strategies should be added or changed?
- How will I reteach weight to those students who did not master it?
- What extension activities would be appropriate for teaching weight?

### The Length of My Feet

### The Area of Things ...

### Grouchy Lessons of Time

### Drop by Drop

### Learning Objectives

Students will:

- Recognize weight as a measurable attribute of objects.
- Measure weight using standard and nonstandard units.

### NCTM Standards and Expectations

- Recognize the attributes of length, volume, weight, area, and time.

- Measure with multiple copies of units of the same size, such as paper clips laid end to end.

### Common Core State Standards – Mathematics

-Kindergarten, Measurement & Data

- CCSS.Math.Content.K.MD.A.1

Describe measurable attributes of objects, such as length or weight. Describe several measurable attributes of a single object.