Math Expressions Grade 2, Unit 3: Length and Shapes
In this unit, your child measures length and studies shapes. They use rulers, yardsticks, and meter sticks, measure one object in two units, estimate before measuring, and compare lengths. They also name triangles, quadrilaterals, pentagons, and hexagons by their sides and angles. It follows their work adding within 200 and leads into subtracting two-digit numbers.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 3?
- Picking the right tool, like a ruler for a pencil and a yardstick for a rug, and measuring from zero. Learn more: Measuring with a ruler, yardstick, or tape
- Measuring the same object in inches and in centimeters, and explaining why there are more centimeters. Learn more: Measuring in inches and in centimeters
- Estimating lengths before measuring, using benchmarks like a fingertip for a centimeter and a ruler for a foot. Learn more: Estimating lengths in inches, feet, and meters
- Comparing two lengths in the same unit, such as finding how many inches longer a pencil is than a crayon. Learn more: Measuring how much longer one thing is
- Naming and drawing triangles, quadrilaterals, pentagons, and hexagons by counting their sides and angles. Learn more: Naming triangles, hexagons, cubes, and more
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
- Pick something to measure, like a bed or a spoon, and ask your child which tool fits best: a ruler, a yardstick, or a measuring tape.
- Play guess and check: before measuring a book or a table, everyone says a guess in inches. Measure together and see whose guess was closest.
- Draw shapes for each other to name. Make one a stretched or tilted hexagon, so your child counts the sides instead of going by looks.
Where kids can get stuck
- Starting a measurement at the 1 instead of zero, so every length comes out one inch too long.
- Guessing wildly, such as a 50-inch pencil, because inches and feet do not feel real yet.
- Thinking only squares and rectangles are quadrilaterals, and leaving out other four-sided shapes.
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
- inch
- A small unit of length, about as long as a small paper clip.
- centimeter
- A tiny unit of length, about as wide as a child's fingertip.
- foot
- A unit of length equal to 12 inches, about as long as a ruler.
- yardstick
- A measuring stick that is 1 yard, or 3 feet, long.
- estimate
- A careful guess about how long or how many.
- unit
- The size you measure with, like an inch or a centimeter.
- quadrilateral
- Any flat shape with 4 sides and 4 angles.
- pentagon
- A flat shape with 5 sides and 5 angles.
- angle
- The corner where two sides of a shape meet.
Want to help your child master measuring and shapes?
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.
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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 Math Expressions Grade 2 Unit 3 cover?
Math Expressions 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.
- 2.G.A.1: Recognize and draw shapes having specified attributes.
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.