Eligibility: All students competing in the fair are eligible.

The Project: The project should involve a significant amount of quantitative measures. It is not necessary for the subject of the project to be measurement or the SI system.

The Use Of SI Units: Ideally, all measures reported in the project including all calculations, results, graphs, etc. should be expressed completely and correctly in units of the International System (SI) also called the metric system. It is preferable that equivalents in other units not be given at all but, if given, they should be secondary to the SI expression. Measurements should actually be made in metric units, not made in old English units and then mathematically converted.

Criteria: Any project which involves measures and expresses those measures consistently and correctly in SI metric would be a good choice to win the metric award. A project which uses a variety of metric units for different kinds of measures (such as force in newtons, pressure in kilopascals, energy in joules, power in watts, etc.) would be a better choice than one which uses only centimeters to measure lengths or liters for volumes. A project in which the measures were integrally important to the research would be a better choice than one in which measures were only used to describe the sizes of containers or the amounts of substances tested (or the size of the display board). Measures which are actually measured in metric should be considered to be better than any made in old English units and only converted to metric. Units of older (non-SI) metric systems are not acceptable. Examples of such non-acceptable units are: mmHg, cmHg or millibars for pressure; calories, kilocalories or ergs for energy or heat; dynes or kilograms-force for force or weight. The accompanying table gives the name and correct symbol for some of the units of the SI system, those for measures that are most likely to be encountered. Also shown are a few other units which are officially considered acceptable for use with SI.

Common Errors: A common error to watch for is the incorrect use of unit symbols. Capital letters are not correct where lower case is prescribed and vice versa. For kilowatts, kW is right while Kw, kw and KW are wrong. The symbols are never followed by an "s" to form a plural. It is not good usage to use multiple slashes for division. Use m/s², not m/s/s. The product of units is formed by a dot (preferably raised) or a space between the separate symbols; e.g., the symbol for the newton-second is N.s or N·s or N s, but not Ns. Symbols should not be mixed with words. Write the symbol km/h or spell out kilometers per hour; do not use kilometers/hour. The symbols are not considered abbreviations so they should not end with a period. The symbols should be used, not abbreviations. Use s rather than sec. and use cm³, not cc or c.c. and use h not hr. etc.

Thank You! The members of the U.S. Metric Association thank you for assisting us by serving as a judge for the metric award.

Columns 1 and 2 of this list do not contain all the quantities and basic units in SI. It includes most of the quantities and basic units that might be expected in the work of good high school science students. Column 3 contains only a couple examples of acceptable multiples and submultiples formed by adding the SI prefixes to the basic unit. There are many others. Any of the prefixes below is correct. Following each is the power of ten it represents and its symbol; e.g. tera represents 10¹² and its symbol is T, as in one terrawatt (1 TW) equals one trillion watts (10¹² W).