2nd Grade · Measurement & Data
2.MD.A.2: Measure the length of an object twice, using length units of different lengths
2.MD.A.2 is a 2nd 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
Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.
In plain words
Measure the length of an object twice, using length units of different lengths.
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
Maria measured her book using small blocks and counted 10 blocks. If she measures the same book using bigger blocks, what will be true about the number of bigger blocks she counts?
- She will count fewer bigger blocks.
- She will count more bigger blocks.
- She will count the same number of bigger blocks.
Where students can get stuck
- Thinking the bigger number means longer, so a book measuring 25 centimeters seems longer than the same book at 10 inches.
- Expecting a bigger unit to give a bigger number, so predicting more feet than inches for the same object.
- Writing a measurement without a unit, such as 25, so no one can tell if it means inches or centimeters.
Effective teaching strategies
- Measure one object twice, once in inches and once in feet, and have students record both numbers with their units side by side.
- Ask students which number is greater, the count of inches or the count of feet, and why the smaller unit needs more copies to cover the same length.
- Have students write a unit after every number, and ask whether two answers, such as 12 inches and 1 foot, describe the same length.
Units that teach this standard
Find where 2.MD.A.2 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.
enVision Mathematics
Eureka Math²
i-Ready Classroom Mathematics
Illustrative Mathematics
Math Expressions
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Measuring in inches and in centimeters 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.