Mathematics
Grade 5
15 min
Add and subtract mixed customary units
Add and subtract mixed customary units
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Add mixed customary units of length (feet, inches) and weight (pounds, ounces), including regrouping.
Subtract mixed customary units of length (feet, inches) and weight (pounds, ounces), including regrouping.
Add and subtract mixed customary units of time (hours, minutes) and capacity (gallons, quarts).
Identify the correct conversion factor needed to regroup between two customary units.
Solve one- and two-step word problems involving the addition and subtraction of mixed customary units.
Clearly explain the process of regrouping (carrying over or borrowing) when working with mixed units.
You're baking a cake that needs 2 pounds 8 ounces of flour, but your bag only has 5 pounds 4 ounces. Do you have enough left to make a second cake? 🎂 Let's fi...
2
Key Concepts & Vocabulary
TermDefinitionExample
Customary UnitsThe system of measurement commonly used in the United States. This includes units for length (inch, foot, yard, mile), weight (ounce, pound, ton), and capacity (cup, pint, quart, gallon).A ruler measures length in inches and feet. A scale measures weight in pounds and ounces.
Mixed UnitsA measurement that includes two or more related units.A person's height might be 5 feet 3 inches. A movie's length could be 2 hours 15 minutes.
Like UnitsUnits that measure the same attribute. You can only add or subtract like units.You add inches to inches and feet to feet. You cannot add inches to pounds.
Conversion FactorThe number that relates two different units of measurement. It's what you use to convert from one unit to another.The conversion fact...
3
Core Formulas
Addition with Mixed Units
1. Add like units. \n 2. If the smaller unit's sum is greater than the conversion factor, regroup.
First, add the quantities for each unit separately. Then, check if the total for the smaller unit can be converted into one or more of the larger units. For example, if you have more than 12 inches, convert them to feet.
Subtraction with Mixed Units
1. Compare smaller units. \n 2. If needed, regroup from the larger unit. \n 3. Subtract like units.
Start with the smallest unit. If the top number is smaller than the bottom number, you must 'borrow' from the larger unit next to it. Convert that one larger unit into its smaller equivalent and add it to the existing smaller units before subtracting.
Key Conversion Factors
1 ft = 12 in \...
4 more steps in this tutorial
Sign up free to access the complete tutorial with worked examples and practice.
Sign Up Free to ContinueSample Practice Questions
Challenging
A bakery starts the day with a 25-pound bag of sugar. They use 8 pounds 12 ounces for a batch of cookies and 10 pounds 8 ounces for a batch of cakes. How much sugar is left in the bag at the end?
A.5 lb 12 oz
B.6 lb 4 oz
C.19 lb 4 oz
D.5 lb 8 oz
Challenging
A delivery driver's first trip takes 1 hour 45 minutes. The second trip takes 2 hours 30 minutes. The third trip takes 1 hour 50 minutes. What is the total time for all three trips?
A.4 hr 125 min
B.5 hr 5 min
C.5 hr 25 min
D.6 hr 5 min
Challenging
After putting a 12-pound 7-ounce turkey in a roasting pan, the total weight on the scale is 15 pounds 2 ounces. What is the weight of the empty roasting pan?
A.2 lb 11 oz
B.2 lb 5 oz
C.3 lb 11 oz
D.3 lb 5 oz
Want to practice and check your answers?
Sign up to access all questions with instant feedback, explanations, and progress tracking.
Start Practicing Free