4th Grade · Measurement & Data
4.MD.A.1: Change larger units into smaller ones, like 4 feet = 48 inches
4.MD.A.1 is a 4th grade Common Core math standard in Measurement & Data. Here’s what it really covers, and how you can help your students learn it.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
The standard
Know relative sizes of measurement units within one system of units including km, m, cm; kg, g; lb, oz.; l, ml; hr, min, sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit. Record measurement equivalents in a two-column table. For example, know that 1 ft is 12 times as long as 1 in. Express the length of a 4 ft snake as 48 in. Generate a conversion table for feet and inches listing the number pairs (1, 12), (2, 24), (3, 36), ....
In plain words
Change larger units into smaller ones, like 4 feet = 48 inches.
Sample questions from student practice
These questions from Bobby's Math Club are the kinds of questions your students will see. You can try answering them to see what a student might see.
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
Where students can get stuck
- Dividing instead of multiplying when changing to a smaller unit, so 4 feet comes out as fewer than 4 inches.
- Assuming every unit works in tens, so 1 hour becomes 100 minutes or 1 pound becomes 10 ounces.
- Trying to convert feet straight into centimeters, when this year's work stays inside one system at a time.
Effective teaching strategies
- Build a two-column table of feet and inches, 1 foot = 12 inches, 2 feet = 24 inches, 3 feet = 36 inches, and have students extend it to 4 feet = 48 inches.
- Ask “more pieces or fewer?” before students convert, so they see that a smaller unit needs a larger number to cover the same length.
- Have students list facts within one system, such as 1 hour = 60 minutes and 1 pound = 16 ounces, to see that units do not all work in tens.
Units that teach this standard
Find where 4.MD.A.1 lands in the program you teach. Each unit has a guide written for families. Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence.
Bridges in Mathematics
enVision Mathematics
Eureka Math
i-Ready Classroom Mathematics
Illustrative Mathematics
Math Expressions
Reveal Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Converting feet to inches and kilograms to grams for a plain-language look at this skill, with three questions to try together and ideas for helping at home.
Help every student practice measurement and data at home
In Bobby's Math Club, students practice 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 for every family.
See how it works for teachers
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.