Illustrative Mathematics Grade 2, Unit 3: Measuring Length
In this unit, your child learns to measure length with rulers, yardsticks, meter sticks, and measuring tapes. They measure in centimeters, inches, feet, and meters, estimate first, compare the same object in two units, and find how much longer one object is. Next, these lengths come together with adding and subtracting on the number line.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 3?
- Measuring with a ruler, yardstick, meter stick, or tape by lining up the zero and reading the end mark. Learn more: Measuring with a ruler, yardstick, or tape
- Measuring the same object in centimeters and in inches and explaining why there are more centimeters. Learn more: Measuring in inches and in centimeters
- Estimating lengths in inches, feet, centimeters, and meters by comparing them to things they know. Learn more: Estimating lengths in inches, feet, and meters
- Comparing the lengths of two objects and writing how much longer or shorter one is. Learn more: Measuring how much longer one thing is
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
A door is measured using which tool?
- Ruler
- Measuring Tape
- Small paper clip
How you can help
- Measure your child's foot and yours in inches, then ask how much longer one is than the other and how they figured it out.
- Before measuring a couch or a bed, ask your child to guess its length in feet, then measure with a tape and check.
- Measure a book in both inches and centimeters and talk about why one number is bigger for the same book.
Where kids can get stuck
- Leaving gaps between paper clips or blocks when measuring, so the length comes out short.
- Overlapping the ruler each time it moves along a long object, so the total comes out too big.
- Writing a measurement with no unit, like 25, so no one knows if it means inches or centimeters.
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
- length
- How long something is from one end to the other.
- inch
- A small unit of length, about the width of a grown-up's thumb.
- foot
- A unit of length equal to 12 inches, about as long as a ruler.
- centimeter
- A small metric unit of length, about the width of a fingertip.
- meter
- A metric unit of length equal to 100 centimeters, a bit longer than a yardstick.
- yardstick
- A measuring stick that is 1 yard, or 3 feet, long.
- meter stick
- A measuring stick that is 1 meter, or 100 centimeters, long.
- estimate
- A smart guess about an amount or a length, made before measuring or counting.
- unit
- The amount you measure with, like an inch, a foot, or a centimeter.
Ready to build your child’s confidence with measuring with rulers?
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 Illustrative Mathematics Grade 2 Unit 3 cover?
Illustrative Mathematics Grade 2 Unit 3 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
- 2.MD.A.1: Measure the length of an object by selecting and using appropriate tools.
- 2.MD.A.2: Measure the length of an object twice, using length units of different lengths.
- 2.MD.A.3: Estimate lengths using units of inches, feet, centimeters, and meters.
- 2.MD.A.4: Measure to determine how much longer one object is than another.
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.