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