# 7.17: Selection of Appropriate Weight or Capacity Units

**At Grade**Created by: CK-12

**Practice**Selection of Appropriate Weight or Capacity Units

Have you ever had an after school job?

Jeffrey is helping his father out as his service station. While Jeffrey is too young to work on cars, he is old enough to stock the shelves. As Jeffrey stocks the shelves, he puts the containers of oil on the shelf. There are many different brands.

Which measurement unit would be used to measure oil?

After Jeffrey finishes that task, he begins counting the bags of ice that are stored in the freezer outside the door. He moves them around and is surprised at how heavy ice actually is.

Which measurement unit would Jeffrey use to measure the weight of each bag of ice?

**This Concept is all about choosing the best unit of weight or measure. These questions will be addressed in the Concept.**

### Guidance

Choosing the correct units can make all the difference for a measurement. You would not measure how tall you are in miles. Neither would you measure length of a football field in inches. The same idea applies for weight and volume. When measuring to cook, it could be pretty complicated if you were trying to measure cups of water in ounces. Think of how challenging that would be as you are measuring. To get an idea of the size of the units of weight and volume, take a look at the table below.

This chart is useful as a reference for many of the different ways to measure weight and capacity.

Which unit would you use to measure each of the following items?

#### Example A

**A baby bottle of milk?**

**Solution: Fluid ounces**

#### Example B

**A cord of wood**

**Solution: Pounds**

#### Example C

**Water for a cake?**

**Solution: Cups**

Now back to Jeffrey and the service station. Here is the original problem once again.

Jeffrey is helping his father out as his service station. While Jeffrey is too young to work on cars, he is old enough to stock the shelves. As Jeffrey stocks the shelves, he puts the containers of oil on the shelf. There are many different brands.

Which measurement unit would be used to measure oil?

After Jeffrey finishes that task, he begins counting the bags of ice that are stored in the freezer outside the door. He moves them around and is surprised at how heavy ice actually is.

Which measurement unit would Jeffrey use to measure the weight of each bag of ice?

First, Jeffrey is wondering about how oil would be measured. Jeffrey has heard his father refer to "quarts of oil." Therefore, the bottles or containers of oil would be measured in quarts.

Ice would be measured in pounds. Ounces would be too small a unit. Pounds is the best choice.

### Vocabulary

Here are the vocabulary words in this Concept.

- Weight
- measurement of the heaviness or mass of someone or something

- Ounces
- the smallest common unit of weight in the customary system, used to measure very small items.

- Pounds
- the most common unit for measuring weight, most things are measured in pounds.

- Tons
- the largest common unit for measuring weight-very large items are measured by the ton-for example, a car or truck.

- Fluid Ounce
- the smallest common unit for measuring liquid capacity. A baby bottle is measured in fluid ounces.

- Cup
- a common small unit for measuring liquid capacity.

- Pint
- 2 cups is equal to one pint of liquid capacity.

- Quart
- 2 pints is equal to one quart of liquid capacity.

- Gallon
- the largest common unit of liquid capacity

### Guided Practice

Here is one for you to try on your own.

If Darcy is filling up her swimming pool, which unit of capacity would she use to measure the amount of water needed?

**Answer**

Darcy would use gallons since fluid ounces is used for smaller quantities of water.

### Video Review

Here are videos for review.

Khan Academy US Customary and Metric Units

James Sousa Converting Between Units of Volume in the Customary System

James Sousa Converting Between Units of Weight in the Customary System

### Practice

Directions: Name the appropriate unit of measure for each item below.

1. The weight of a dog

2. The weight of a camper

3. Soda in a can

4. Two Elephants

5. A television set

6. A baby bottle

7. A jug of milk

8. An automobile

9. The water in a pool

10. A pile of pennies

11. A pallet of wood pellets

12. A rhinocerous

13. A boat

14. An apple

15. Water in an eye dropper

Cup

A cup is a small customary unit for measuring liquid capacity. One cup is equal to eight ounces or about 0.25 liters.Customary System

The customary system is the measurement system commonly used in the United States, including: feet, inches, pounds, cups, gallons, etc.Fluid Ounce

A fluid ounce is a customary unit for measuring liquid capacity. Soft drinks are measured in fluid ounces.Gallon

A gallon is a unit of liquid capacity. One gallon is equivalent to four quarts.Ounces

Ounces are the smallest common unit of weight in the customary system, used to measure very light items.Pint

A pint is a unit of liquid capacity. One pint is equivalent to two cups.Pounds

Pounds are one of the most common units for measuring weight.Quart

A quart is a unit of capacity that is equivalent to two pints.Ton

A ton is the largest common unit for measuring weight. Very large items like cars and trucks are measured in tons.Weight

Weight is a measurement of the heaviness or mass of someone or something. The customary units of weight included ounces, pounds, and tons.### Image Attributions

Here you'll learn to choose appropriate customary units of weight or capacity given different measurement situations.