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Ready, Set, Build: Using Lego to Practice Taking Measurements

Grade: 2-3

Subject: Math

Standards of Measurement

  • "Understand measurable attributes of objects and the units, systems, and processes of measurement."
  • "Apply appropriate techniques, tools, and formulas to determine measurements."
  • "Understand that measurements are approximations and how differences in units affect precision."

Lesson Objective: 

Third-graders are exploring their world and are beginning to formulate their thoughts about school and education based on their experiences. To create a positive experience at school and help students retain information, instructors must offer opportunities to apply lesson plans to tangible examples and allow children to experience the lesson with real-life application. This lesson is all about engaging students in this manner. 

By the end of this lesson, students will have met several requirements set by the National Council of Teachers of Mathematics, including measuring length. Ultimately, students can take and record accurate measurements at the end of this lesson using a set unit.


  • Lego bricks (At least 5-10 bricks per student or pairing)
  • Ruler
  • Blank paper
  • Pen or marker for each student
  • Homework worksheet


Ask: "Do you know how to take measurements?" (Allow a few minutes to discuss the concept of measuring to gauge students' understanding of the terminology. Explain any terms that need explaining, including units and the use of each tool.)

Say: "Today, we are going to learn all about measuring. We have learned much about math; I know you all know how to count and read numbers. Now, we'll use all that knowledge to determine different objects' sizes."

Say: "Let's start by seeing how long our arms are. Maybe we can measure everything with our arms!" (Here, students will use their rulers to see how long their arms are. Walk around to observe and help students understand where to look to read measurements. Have every student write down the approximate length of one arm in inches.)

Say: "Did everybody get the same measurement? How long is your arm?" (Ask a few students to share their answers; answers will vary.) 

Say: "So, an arm's length isn't a standard unit of measurement, huh? I guess we can't measure using our arms. That's why we need something called a unit. We can measure things using different units, like inches and centimeters. These are two different ways to measure length. We're going to practice now, but with Lego! 

(Bring out the box of Lego bricks. Depending on what is available, you might put a few pieces on each table or in the middle of the floor to divide materials among students. Now, students will start the activity either in groups or independently.)


  1. Instruct students to divide their paper into two columns. 
  2. Next, have students label each column. There will be a column for the item name and a column for length in Lego unit(s). 
  3. Next, each student will use Lego to build a tower or a row of Lego bricks. To do this, stack 5-10 Lego bricks on top of each other. The Lego bricks will click into place, keeping them secure and rigid for measuring items.
  4.  Students will begin measuring and recording their data in a group of two or as an individual. Students can measure anything in the classroom. They will need to write down the item name and length of the item in Lego. For example: 
    1. Shoe: 6 Lego bricks
    2. Pencil: 4 Lego bricks
    3. Door: 32 Lego bricks
    4. Sarah: 23 Lego bricks
    5. Backpack: 7 Lego bricks


  1. To measure items larger than 10 Lego bricks, students can team up to create larger/longer Lego towers.
  2. Students should measure between 10-15 items in the classroom.
  3. Lego measurements will depend on the size of Lego bricks you can access. There are small Lego bricks and large Duplo Lego bricks. It does not matter which type you use as long as you have enough of each type. 


Once students are done measuring items, you can conduct a class discussion to compare measurements. If any items have varying results you can remeasure the item as a class. For example, one student measured a desk at 13 Lego bricks while another measured the desk at 17 Lego bricks. Measure as a class to determine the correct height. 

To drive home the point, assign a measurement worksheet as homework, but instead of Lego bricks, students will measure using any available "unit" they have. Such as a shoe, pencil, wooden blocks, etc. 

Written by Melanie Barrozo
Education World Contributor
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