Metric Prefixes: Is It Deca- Or Deka-?

The SI (metric) prefix deca is 101. For example, one decameter equals 10 meters and five decagrams equals 50 grams. But... sometimes deca is written deka.

"You say tomato and I say tomahto"... says deca, but says deka. They both agree that the abbreviation is da.

Russ Rowlett's "How Many? A Dictionary of Units of Measurement" at does provide the following clarification.

   "The SI Brochure spelling of this prefix is deca-, but the 
    U.S. National Institute of Standards and Technology (NIST) 
    recommends deka-. National variations in spelling of the 
    prefixes are allowed by the SI."

SCC's President is Dr. Art DeCabooter (not DeKabooter).

  1. one decabooter = _________ booters

  2. ___________________ nanobooters = one decabooter

  3. No or Yes: If a=2, r=5, t=0.1, then art decabooter equals one decabooter.

Creator: Gerald Thurman []
Created: 05 March 2008

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