January 2004 Tip
Metric measurement doesn’t have to be a mystery! In fact, it’s really easy to ring in the New Year with an understanding of the metric system. Whether your students are still in the nonstandard, approximating-standard-units, measuring- using-standard-units or solving-problems-using-measurement stage, building an understanding of the metric system is as simple as pulling out your base ten materials.
The metric system is actually a “new” system of measurement, having been developed in 1790 due to a need in a global society for standardized measurement in commerce, engineering, science, etc. Based in nature, the length unit, or meter, is one ten-millionth the distance from the North Pole to the equator. For more information on the system, begin with the World Book Online Reference Center:
Bruce B. Barrow, " Metric system " World Book Online Reference Centre, http://www.worldbookonline.com/ar?/na/ar/co/ar358560.htm, December 29, 2003 (the above link works if you have a World Book Online subscription).
Unlike our customary system, the metric system is interrelated. Once students learn the relationship among the unit and various prefixes, they can apply the knowledge to all metric measurement strands. Beginning with the base ten materials helps students visualize those relationships.
We hope that the following pages will help you and your students in building an understanding of this easy to learn system. By the way, did you know that the United States is the ONLY industrialized nation in the world that does not use metric as its standard measurement system?
The Basics
The metric system is a decimal system, or base-ten relationship. Units then are increased or decreased in powers of ten just like our place value system. (Note that metric symbols are small letters, no period. The only exception is the liter which in the US is usually denoted with a capital L to differentiate from a 1 with which a small “l” might confuse.)
The base unit for the entire system is the meter (m).
If you break the meter into 10 equal parts, each part is named a decimeter (dm).
And if you break the decimeter into 10 equal parts, each part is named a centimeter (cm).
Using the base ten model, the unit cube becomes the centimeter, the ten or long becomes the decimeter, and 10 of those longs taped together in long line become the meter. In fact, your base ten cube is a centimeter cube. That is, all edges measure 1 cm.
It’s important for students to benchmark to the world around them. Regardless of the age of the students, if they have not had tactile experience with measuring in metric, the following should prove helpful.
Give each student a base ten unit. Have them use that unit throughout the week to find things that measure “about” as long as one of the edges. Collect the list of items on a room chart. If students are old enough to use rulers, have them discern at the middle of the week that the edges of the cube are a cm long. At the end of the week, talk about all of the things that measure about 1 centimeter long.
Repeat the process the following week for a decimeter using a base ten long. On the third week use a piece of ribbon cut the same length as 10 longs placed end to end.
