Go Math! Grade 4, Chapter 12: Relative Sizes of Measurement Units
In this unit, your child compares the sizes of measurement units for length, weight, liquid volume, and time, in both customary and metric units, and converts larger units to smaller ones. They solve story problems about elapsed time, distance, and money, often with a number line. It follows the angle unit and leads into perimeter and area.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 12?
- Converting customary and metric units, like 3 pounds to 48 ounces or 5 meters to 500 centimeters, and making tables. Learn more: Converting feet to inches and kilograms to grams
- Solving elapsed-time and money problems on a number line, such as how long a game from 2:45 to 4:10 lasted. Learn more: Story problems about distance, time, and money
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
Amara buys a 5-pound bag of oranges. How many ounces does the bag weigh?
- 60 ounces
- 21 ounces
- 80 ounces
How you can help
- Pour drinks from a 1-liter bottle at a party and read the label. Ask how many 200-milliliter cups it fills, and how your child knew to change liters to milliliters first.
- Weigh fruit on a store scale. If a bag of apples is 3 pounds, ask your child how many ounces that is, and why it's 48.
- Time a soccer practice or a park visit. If it starts at 2:45 and ends at 4:10, have your child count on in jumps to find 1 hour 25 minutes.
Where kids can get stuck
- Treating time like ordinary numbers, so 9:50 plus 20 minutes becomes 9:70.
- Getting fewer inches than feet, by dividing when changing to the smaller unit.
- Mixing up which unit is larger, like thinking a gram is heavier than a kilogram.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- convert
- To change a measurement into a different unit, like 3 feet into 36 inches.
- customary units
- Units like inches, feet, pounds, and cups that are used in the United States.
- metric units
- Units like meters, grams, and liters, where each unit is based on tens.
- ounce
- A small unit of weight; 16 ounces make 1 pound.
- pound
- A unit of weight equal to 16 ounces.
- centimeter
- A small metric length; 100 centimeters make 1 meter.
- elapsed time
- How much time passes between the start and the end of an event.
- number line
- A line with numbers at equal distances, used to show and compare amounts.
Want to help your child master measurement units?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
Join the club
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Go Math! Grade 4 Chapter 12 cover?
Go Math! Grade 4 Chapter 12 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.