# US Customary units of weight review (oz & lb)

CCSS Math: 5.MD.A.1
Review the size of ounces and pounds and how to convert between the two.  Then, try some practice problems.

## Customary units of weight

Weight is a quantity of heaviness. For example, you are measuring the weight of your body when you step on to a scale.
In the customary system of measurement, the most common units of weight are the ounce (oz) and pound (lb).

### How much is an ounce?

A slice of bread has a weight of about $1$ ounce:

### How much is a pound?

A soccer ball has a weight of about $1$ pound:

## Practice set 1: Estimating weight

Problem 1A
Identify the most reasonable unit to measure the weight of a refrigerator.

Want to try more problems like this? Check out this exercise.

## Converting pounds to ounces

$1 \text{ pound} = \green{16}\text{ ounces}$
To convert pounds to ounces we multiply the number of pounds by $\greenD{16}$.
Example:
$\pink{30} \text{ pounds}= \pink{30}\times\green{16}=\blue{480}\text{ ounces}$

## Converting ounces to pounds

$1\text{ ounce}= \dfrac1{\green{16}} \text{ pound}$
To convert ounces to pounds we divide the number of ounces by $\greenD{16}$.
Example:
$\pink{112} \text{ ounces}= \dfrac{\pink{112}}{\green{16}}=\pink{112}\div\green{16}=\blue7\text{ pounds}$
$9$ pounds $=$