How to Remember the Metric Prefixes

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The metric method of measurement -- using kilos and meters rather than pounds and feet -- is used in everyday life in most countries of the world and everywhere in the scientific and medical communities.

In the metric system, measurement increments are by factors of 10: 100 centimeters make a meter, and 1,000 meters make a kilometer. For those who have grown up thinking of inches, feet and yards, remembering which prefix increases or decreases your measurement can be a challenge.

    There are twenty prefixes. Ten prefixes increase the basic unit -- gram or meter -- by factors of 10: deca, hecto, kilo, mega, giga, tera, peta, exa, zeta, yotta. Ten more decrease the basic unit by factors of 10: deci, centi, milli, micro, nano, pico, femto, atto, zepto, yocto.

    Write out the prefix chart by hand and post it where you will see it often, perhaps over your desk. It may be tempting to print it out from your computer, but writing it yourself will begin to seat the prefixes in your memory.

    The mnemonic for the six most commonly used prefixes from kilo to milli is King Henry Didn't Drink Chocolate Milk. You may also include a B for the base unit in the middle of the chart -- King Henry Died By Drinking Chocolate Milk. This is the acrostic method of memorizing.

    Choose one of these sentences and memorize the most commonly used six prefixes by reciting this mnemonic.

    Expand to all 20 prefixes. You can make up your own mnemonic, or you can use the one here. Rather than composing one long sentence, create several short ones. When you break up a long string of data into smaller groups, this is called chunking. Think of words which are similar to the prefixes, as this will help you remember them.

    Yes, Zelda Eats Pita. Terry Gages Measures. King Henry Didn't Drink Chocolate Milk. Ms. Nancy Picks Feminism. All Zebras Yodel.

    Intersperse the prefix names between the mnemonic words and recite them aloud, as follows.

    Yes -- yotta; Zelda -- zetta; andEats--exa; Pita -- peta. Terry -- tera; Gages -- giga; and Measures -- mega. King -- kilo; Henry -- hecto; Didn't -- deca; Drink -- deci; Chocolate -- centi; and Milk -- milli. Ms. -- micro; Nancy -- nano; Picks -- pico; and Feminism -- femto. All -- atto; Zebras -- zepto; and Yodel--yocto.

    Put your mnemonic to music. Use the tune to a rock or rap song that you like. Sing the mnemonic as you go about your day. Dancing to the music as you sing aloud will also help the memorization process.


About the Author

Gale Macaulay-Newcombe has been writing professionally since 1988 and was first published in 2004 in "The Standards for Certification" of the Canadian Association for Pastoral Practice and Education. A certified teaching supervisor (retired), Macaulay-Newcombe holds a Bachelor of Arts in English from the University of Guelph and a Master of Divinity from McMaster University.