The Metric System Stair-Step Conversion Practice

by Amanda L. Smith

Gardener’s: Linguistic; Visual-Spatial; Bodily-Kinesthetic; Interpersonal; Logical-Mathematical
Bloom’s: Knowledge; Comprehension; Application

CA State Standards:
Investigation and Experimentation (Middle School grades 6-8)

Anticipatory Set/Objective:

• Students will be able to: State the values of and abbreviations for each of the prefixes used in the metric system.
• Students will be able to: Convert from one subunit to another subunit within a given unit of the metric system.

Key Vocabulary:
Length: the longest dimension of an object

Mass: the amount of matter in an object

Volume: the amount of space an object takes up

Gram: base unit of measure used for mass in the metric system

Liter: base unit of measure used for volume in the metric system

Meter: base unit of measure used for length in the metric system

Milli-: a prefix in the metric system denoting a factor of one thousandth (10-3)

Centi-: a prefix in the metric system denoting a factor of one hundreth (10-2)

Deci-: a prefix in the metric system denoting a factor of one tenth (10-1)

Deka-: a prefix in the metric system denoting a factor of ten (101)

Hecto–: a prefix in the metric system denoting a factor of one hundred (102)

Kilo: a prefix in the metric system denoting a factor of one thousand (103)

Materials:

• Metric rulers
• Metric meter stick
• Metric System Stair-Step Conversion Practice worksheet/handout
• Additional set of metric conversion practice problems (and answer key)- provided by teacher
• Post-it notes (or half sheets of lined paper)
• optional: mini whiteboards and dry erase markers
• optional: create a handout or PowerPoint presentation from this website to introduce the homework http://www.metric4us.com/why.html

Introduction & Modeling:
Students will be shown a metric ruler and meter stick, and asked how these are organized. The teacher will explain that every metric device is arranged in factors of 10 (e.g., 10 cm = 100 mm; 1 m = 100 cm). This will be the basis of the lecture and further conversion discussions in class.

Guided Practice:
Students will be given the Metric System Stair-Step Conversion Practice worksheet, and the teacher will go over the basic conversion step method. Teacher can verbally say, “to the left, you divide!” and “to the right, multiply!” with enthusiasm while explaining to the class.

Use an overhead projector, digital projector, or draw the stair-step image on the whiteboard to help the students visualize how to move about the stair steps as you demonstrate the example problems with the class. Make sure to verbalize the phrases (as shown above) for each example problem you do with the class, and have your students use your finger to move from step-to-step with you as you demonstrate on the board.

If you want to add in one additional learning tool, ask your students to stand up behind their desk chair, and prepare them for the Metric Mantra and Dance. Recite the following example aloud to the class: “Okay class, we are going to convert from gram to kilogram…so we will dance/shuffle/move to the LEFT 3 times…here we go!”. (as the students move to the left, have them recite “to the left, to the left, to the left…MULTIPLY!” as they move the 3 steps). Do a few of these conversions while the students move to the left or right, and have them recite the mantra while they move through the classroom. This is a great way for the students to gain a basic understanding of how many times to move left or right (moving to the right, say, “to the right, to the right…WE DIVIDE!”. This will take some practice, but students will have a better understanding of the metric conversions if you put in the time. (plus, students always love to get up and move around when it is constructive learning).

Independent Practice:
Students will do seat work practice problems (options: mini whiteboards and dry erase markers are always fun and provide quick informal assessment; pencil and paper worksheet(s); or teacher can put problems on the board for students to do on their own). After students complete the assignment, make sure to provide answers to each practice problem, and demonstrate on the board how to use the stair-step method (and maybe even throw in a few dance moves and mantra reciting if the students are doing a good job!).

Closure:
Near the end of the class, review with students the steps you need to follow to make metric to metric conversions by randomly calling on students. Then the teacher will give each student a post it note (or just a small half sheet of paper will be fine), then write one last problem on the board such as 0.000652 kg = _______ mg and ask students to write their answer to the problem.(Personally, I would try to make it a more challenging problem) . As students leave they will hand the teacher their post-it note with their answer. (This will give you one more quick chance to assess their understanding, and see if they are able to do a more complex problem before tomorrow’s lesson or to be able to complete tonight’s homework).

Homework:
Provide students with a brief history of the attempts of the United States to convert to the metric system, and some of the debates that occurred. (The teacher may want to use this website, http://www.metric4us.com/why.html to create a handout or PowerPoint presentation to introduce the topic.)

Students will do a free-write using these discussion questions as a guideline: Why do you think it would be so hard for the United States to switch to the metric system? Do you think it is in the country’s best interest to overcome these difficulties? Why or why not? Do you think it is confusing that the United States uses a different measuring system from the rest of the world? What kinds of problems arise because of the use of a different measuring system?

Extra Credit or Extension Activity for Gifted Students:
Students will write a story, journal entry, or letter about a typical day if they were to wake up in a world that used only the metric system. The teacher will encourage the students to include more examples of metric measurements in their daily life, such as speed limit signs and the price of gas per liter.

Amanda L. Smith is a science teacher at Wilder’s Preparatory Academy Charter School and a member of CSTA.

Powered By DT Author Box

Written by Amanda Smith

Amanda Smith is a teacher at Wilder’s Preparatory Academy Charter School and a member of CSTA Publications Committee.