2nd Grade · Measurement & Data
2.MD.D.9: Generate measurement data by measuring lengths of several objects
2.MD.D.9 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
Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.
In plain words
Generate measurement data by measuring lengths of several objects.
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
Sarah measured the length of her crayons. She found lengths of 5 inches, 6 inches, 5 inches, 7 inches, and 6 inches. How many crayons were 5 inches long?
- 2
- 5
- 1
Where students can get stuck
- Spacing the numbers unevenly, or leaving out a number nobody measured, such as skipping 8 when no object was 8 inches.
- Drawing the Xs in different sizes or spacing, so the stacks are hard to compare.
- Rounding inconsistently, recording a pencil a little over 5 inches as 6 inches instead of 5.
Effective teaching strategies
- Have students measure several pencils to the nearest inch and record each length in a list before they make the line plot.
- Draw a number line with equal spacing that shows every whole number from the shortest to the longest length, including numbers with no data, and stack same-size Xs above each measurement.
- Agree on a rule for the nearest whole unit, such as recording 5 inches when the end falls closer to the 5 than to the 6, and use it on every object.
Units that teach this standard
Find where 2.MD.D.9 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
Go Math!
i-Ready Classroom Mathematics
Reveal Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Measuring things and making a line plot 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.