Permacharts has published a Metric System Quick Reference Guide (A-859-1G, last updated in 2018) in a handy, fold-over, laminated form, which clearly and concisely defines and illustrates metric units with easy-to-understand illustrations, both scientific and practical. A surprising amount of information is conveyed in just four pages. The first two pages provide a general introduction to the metric system and its supplementary units (radian and steradian), then detail the base units for length, temperature, mass, luminous intensity, time, quantity of matter, and electric current. The chart provides pertinent usage guidance, such as "The use of [angular] minutes and seconds is discouraged. Decimal divisions of a degree should be used."
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