The official birth of the metric system took place on this date in 1796.

Standards for weights and measures have varied widely in different parts of the world throughout history. In some cultures, standards developed that were not uniform, such as the cubit (the distance from a man's elbow to the middle finger). Such standards were useful for rough estimates, but since men's arms varied in length, no precision was possible. In many places, standards did develop that were uniform, but the accepted standard differed depending on your location. In 18th Century France, for example, there were measurements roughly equivalent to the British foot and inch, but they differed slightly from province to province. In order to do away with this confusion and lack of uniformity, French scientists began to develop a series of fixed measures based on agreed standards. The original length of the metric meter was determined by surveying the length of one quadrant of the earth and dividing that figure by ten million. Since then, the standard used to determine the length of the meter has changed several times. Today, a meter is the distance that light travels in a vacuum in 1/299,792,458 second. The date chosen as the metric system's birthday—10/10—was selected as an homage to the base-ten decimal system used in this new system of fixed measures.

 

Illuminations
Judge and Jury (Pre-K–2) helps students use games to understand concepts in measurement and statistics. Students are asked to measure distances using standard and nonstandard units and to record their measurements in various tables. Then they are asked to use descriptive statistics to report the results.

In Numerical and Categorical Data (3–5), students consider how to obtain measurements and record data. In collecting data, students measure with standard units and carry out simple unit conversions, such as from centimeters to meters or feet to inches.

In the nine-lesson unit Measuring Up (6–8), students engage in a variety of activities that involve taking their own measurements, exploring different ratios, examining similar figures and converting measurements into customary and metric units.

In one lesson from the unit, Do You Measure Up? (6–8), students learn the basics of the metric system.