bell ringer get out a sheet of paper… what is the metric system based on?
TRANSCRIPT
Bell Ringer
• Get out a sheet of paper…
• What is the metric system based on?
The Metric System
• The metric system is an internationally standardized system of units of measurement.
• The metric system is based on a base unit and prefixes.
HistoryHistoryThe metric system was created to develop a unified, natural, universal system of measurement. In 1790 King Louis XVI of France assigned a group to begin this task. As of 2005, only three countries, the United States, Liberia, and Myanmar, have not changed over to the metric system. The official modern name of the metric system is the International System of Units or abbreviated SI.
The SI system is used universally for all scientific purposes so the metric system will be the only system of measurement we will be using in science this year.
The metric system was developed based on decimals. The base units are converted by factors of 10 by simply moving the decimal place. A prefix is then added to the base unit to indicate a larger or smaller unit.
The base unit for length is the meter. The meter was originally defined as 1/10,000,000th of the distance from the North Pole to the Equator through Paris. The meter is now defined as the distance traveled by light in an absolute vacuum in 1/299,792,458 of a second (don’t worry – you don’t have to remember this).
The base unit for mass in the metric system is the gram. Mass is a measurement of how much matter is in an object. Mass is measured using a balance. One gram is about the same as a small paper clip.
Double pan balance
Triple beam balance
Mass of about one gram
Volume is the measurement of how much space an object occupies. Liquid volume is measured with a graduated cylinder. Solid volume can be calculated with a formula or by water displacement. The basic unit for volume in the metric system is the liter. One liter sodas can be
purchased at convenience stores.
Water displacement
Graduated cylinder
Volume formula for a rectangular prism is length x width x height.
Temperature is the measurement of the heat of something on a scale. The basic unit of temperature in the metric system is Celsius or centigrade. Water freezes on the Celsius scale at 0° and boils at 100°. Temperature is measured with a thermometer.
Thermometer
Water at freezing point measured by a digital thermometer
The metric system uses prefixes added to the base unit to represent larger or smaller units. Each prefix is a multiple of 10.
Prefix Abbreviation Word value Number value
kilo km one thousand
1000
hecto hm one hundred 100
deka dam ten 10
deci dm one tenth 0.1
centi cm one hundredth
0.01
milli mm one thousandth
0.001
Length Units in Metric System
kilometer
hectometer
dekameter
meter
decimeter
centimeter
millimeter
Most Common Volume Units in Metric System
liter
milliliter
Most Common Mass Units in Metric System
kilogram
gram
milligram
Metric mass can be expressed in terms of metric volume. One gram of mass equals one milliliter in volume. One milliliter equals one centimeter cubed.
If one milliliter equals one gram then 1000 milliliters or 1 liter equals 1000 grams or 1 kilogram.
kilogram/liter
KILO1000Units
HECTO100
Units
DEKA10
UnitsDECI
0.1Unit
CENTI0.01Unit
MILLI0.001Unit
MetersLitersGrams
Ladder Method
How do you use the “ladder” method?
1st – Determine your starting point.
2nd – Count the “jumps” to your ending point.
3rd – Move the decimal the same number of jumps in the same direction.
4 km = _________ m
12
3
How many jumps does it take?
Starting Point Ending Point
4.1
__.2
__.3
__. = 4000 m
Try these conversions using the ladder method.
1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm
14 km = _______ m 109 g = _______ kg 250 m = _______ km
Conversion Practice
Compare using <, >, or =.
56 cm 6 m 7 g 698 mg
Write the correct abbreviation for each metric unit.
1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____
2) Meter _____ 5) Millimeter _____ 8) Centimeter _____
3) Gram _____ 6) Liter _____ 9) Milligram _____
Try these conversions, using the ladder method.
10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm
11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km
12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg
13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm
14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g
Metric Conversion Challenge
Compare using <, >, or =.
25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 mL 1.5 L
26) 536 cm 53.6 dm 28) 43 mg 5 g 30) 3.6 m 36 cm