SI - metric system
The SI System
- SI is the modernized version of the metric measurement system. (Système International d'Unités)
- The metric system is based on seven base units.
- SI measurements are expressed with decimals, not fractions (1.5 , not 1 ½)
- Other measures of length are based upon multiplying or dividing the meter by 10.
- A prefix is added to the word 'meter' to describe these other measures.
- The meter is the unit of length used in the SI measurement system.
- In 1793, the meter was defined as 1/10,000,000 of the distance from the pole to the equator.
- Over the years, standard meter length bars of brass, platinum, and platinum-iridium were used.
- In 1983, the length traveled by light in vacuum during 1/299,792,458 of a second was defined as one meter.
mega (M_): 1,000,000 of the base units (106).Example 1,000,000 meters = 1 Mm
kilo (k_): 1,000 of the base units (103).Example 1000 meters = 1 km
centi (c_): 1/100 of the base units (10-2).Example .01 meters = 1 cm
milli (m_): 1/1000 of the base units (10-3).Example .001 meters = 1 mm
micro (µ_):1/1,000,000 of the base units (10-6) .Example .000001 meters = 1 µm
nano (n_): 1/1,000,000,000 of the base units (10-9) .Example .000000001 meters = 1 nm
pico (p_): 1/1,000,000,000,000 of the base units (10-12).Example .000000000001 meters = 1 pm
- 1 meter = 100 centimeters = 1000 millimeters
- 1 m = 100 cm = 1000 mm
- 1 cm = 10 mm
Using a meter stick, answer these questions:
- My hand span is ________ centimeters. (Measure outstretched hand between tip of thumb and tip of little finger)
- The width of my _____________ fingernail is 1 cm. (Find the fingernail that is the closest)
- The width of the back my hand is _________ cm. My height is _____________ m.
- The width of my table is ___________ m.
- The table length is ___________ m.