## Whale Weight

In this lesson, students investigate relationships between numbers, identify number patterns,

represent the information in graphic chart form, and generalize the results of an investigation. Specifically, students explore the relationship between a whale's length and its weight.

Ask students to describe the relationship between inches, feet, and yards. Possible responses will include:

12 inches = 1 foot 3 feet = 1 yard

Ask students to describe the relationship between pounds and tons. One possible response will be:

2000 pounds = 1 ton

Give students some sample problems to complete individually to review how to work within the customary system. For example, you can write the following problems on the chalkboard or overhead:

36 feet = ____ yards [solution: 3 yards]

30 inches = ____ feet [solution: 2.5 feet]

5 1/3 yards = ____ feet [solution: 16 feet]

8,000 pounds = ____ tons [solution: 4 tons]

1.5 tons = ____ pounds [solution: 3,000 pounds]

Distribute the Whale Weight Activity Sheet to each student.

Review the directions, encouraging students to study the information given.

Give students time to complete the chart and make a generalization. This can be done in pairs.

As a class, discuss the generalization that a gray whale's estimated weight is about 1,000 pounds, or a half ton, for every foot of its length.

**Assessment Option**

You may collect the Whale Weight Activity Sheet as a means of assessment. The solutions to chart are as follows:

- 30 feet; 30,000 pounds (or 15 tons)
- 12 yards; 36,000 pounds (or 18 tons)
- 48 feet (or 4 yards); 48,000 lbs
- 25 feet; 25,000 pounds
- 28 feet; 13 tons plus 2,000 pounds
- 50 feet; 50,000 pounds
- 44 feet; 22 tons
- 600 inches; 50,000 pounds (or 25 tons)
- 42.5 feet; 42,500 pounds
- 38 feet; 38,000 pounds
- 15 1/3 yards; 46,000 pounds (or 23 tons)
- 39.5 feet; 39,500 pounds

**Extensions**

- Express all table lengths in feet and all weights in tons.
- Rank the whales by weight from the heaviest to the lightest (note that whales 6 and 8 have equal weights).

### Skin Weight

### Learning Objectives

Students will:

- Investigate the relationship between pairs of numbers.
- Identify number patterns.
- Represent the information in graphic chart form.
- Generalize the results of an investigation.

### NCTM Standards and Expectations

- Represent, analyze, and generalize a variety of patterns with tables, graphs, words, and, when possible, symbolic rules.

- Understand both metric and customary systems of measurement.

- Understand relationships among units and convert from one unit to another within the same system.

### Common Core State Standards – Practice

- CCSS.Math.Practice.MP8

Look for and express regularity in repeated reasoning.