Illuminations: What Should I Measure Next? How About Me!

What Should I Measure Next? How About Me!

Measuring Me

Students use yarn to measure lengths such as arm span and height. This gives the students practice measuring with nonstandard units. Pairs of students also compare their height and arm spans. They practice problem-solving and reasoning skills by discussing why there are similarities and differences between the lengths of yarn that represent arm spans and height.

Learning Objectives
 
Students will:
  • use nonstandard units to measure heights and arm spans
  • compare lengths and discuss why the measurements might differ
  • use problem-solving and reasoning skills by discussing similarities and differences

Materials
 
Markers
Scissors
Yarn
Tape
Resealable plastic bags labeled with students' names
Comparing Classmates Activity Sheet

Instructional Plan

To introduce the lesson, gather the whole class in an area of the room. Ask a student to volunteer to be measured. Have the student extend his or her arms straight out to his or her side. Using yarn, demonstrate how to measure arm span, the distance from fingertip to fingertip. Cut the yarn and label it with the student's name and the words, "arm span."

 

 

Measure the student's height from the top of his or her head to the floor. Cut the length of yarn and label it with the student’s name and “height.”

 

 

Measure the length of the student's legs from floor to waist. Label the yarn lengths with the student’s name and the word "leg to floor". Measure the student’s length from waist to floor and label the yarn. Invite the students to ask questions about the processes you demonstrated.

Group students in pairs and have them measure each other's arm span, height, and leg length from waist to floor. Remind them to label the yarn lengths appropriately. Have the pairs of students compare the length of their arm spans and heights.

As you move among the students, ask them to explain why all arm spans, heights, and leg length are not the same.

After students finish measuring, they should move around the room to find a partner who meets one of the following criteria:

  • Same height
  • Different heights - I am taller than my partner (or, my partner is shorter than me)
  • Different heights - My partner is taller than me
  • Same arm spans
  • Different arm spans - I have a longer arm span than my partner (or, my partner has a shorter armspan than me)
  • Different arm spans - My partner has a longer arm span than me

 

Students can repeat the above activity to find a partner for each of the six criteria listed. Students may also record this information on the Comparing Classmates Activity Sheet.

Comparing Classmates Sheet Comparing Classmates Activity Sheet

Label a resealable plastic bag for each student to store his or her yarn for the next lesson. Collect the bags for safe storage.

Questions for Students
 

What did you notice when you compared your arm spans? Why were the arm spans alike? Why were they different?

What did you notice when you compared your height with that of your partner? Why were the heights alike or different?

What did you notice when you compared the length of your leg with that of your partner's leg? Why were the lengths alike or different?

Assessment Options
 
  1. At this stage of the unit, students should be able to do the following:

    • Use nonstandard units to measure their height, arm span, and lengths of other parts of their body
    • Use nonstandard units to measure arm span, height, and length of leg from waist
    • Explain why arm spans and heights differ in length
  2. Record the names of the students who are unable to measure using yarn as a nonstandard unit. Provide extra experiences for these students. If some students are unable to successfully compare lengths, pairing them with students who are successful might be helpful. When the students are unable to defend their answers, it may result from a lack of understanding of the mathematical concepts or a lack of knowledge of vocabulary words to describe what they are doing.

Extensions
 
  1. Students who have already grasped the concept of measuring with nonstandard units may wish to estimate how many inches tall they are. Then, they can use yard sticks to measure the lengths of yarn representing their heights, and compare their estimates to the actual lengths. Students may do the same for their arm spans.

Teacher Reflection
 
  • Which students were able to measure the length of arm span and height of body with nonstandard units? Which were not?
  • Which students were unable to successfully compare the lengths of yarn? What caused them difficulty? What learning experiences do they need?
  • What connections did students make that surprised you?

NCTM Standards and Expectations
 
Measurement Pre-K-2
  1. Recognize the attributes of length, volume, weight, area, and time.
  2. Select an appropriate unit and tool for the attribute being measured.
  3. Understand how to measure using nonstandard and standard units.
This lesson prepared by Carol Midgett.
  
1 period   

NCTM Resources

Principles and Standards for School Mathematics
National Council of Teachers of Mathematics Thinkfinity Verizon Foundation
More and Better Mathematics for All Students
© 2000 National Council of Teachers of Mathematics
Use of this Web site constitutes acceptance of the Terms of Use

The National Council of Teachers of Mathematics is a public voice of mathematics education, providing vision, leadership, and professional development to support teachers in ensuring mathematics learning of the highest quality for all students. The views expressed or implied, unless otherwise noted, should not be interpreted as official positions of the Council.