The Metric System

Available at http://www.redwood.org/st

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Background

• The system of measurement used today by scientists in all countries of the world is called the metric system. The metric system is a decimal system, meaning it is based on the number ten and multiples of ten, such as 100 and 1000. This handout will act as your reference to the metric system throughout Integrated Science 1 and 2.

Unit: Length [typical tool used = meter stick]

• Length is the distance from one point to another. The basic unit of length in the metric system is a meter (m). A meter is slightly longer than a yard.

• 1 meter (m) = 100 centimeters (cm)1,000 meters = 1 kilometer (km)

• 1 meter (m) = 1,000 millimeters (mm)

1 centimeter = 10 millimeters (mm)• 1 meter (m) = 1,000,000 micrometers (µm)

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Green line is 2.6 cm or 26 mm.

Unit: Volume [typical tool used = graduated cylinder]

• Volume is the amount of space an object takes up. The basic unit of volume in the metric system is a liter (l).

• 1 liter (l) = 1,000 milliliters (ml)

= 1000 cubic centimeters (cm3)

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Unit: Temperature [typical tool used = thermometer]

• Temperature measures the average kinetic energy of the particles in a substance. Kinetic energy is the energy of motion. More energy = more particle motion = higher temperature. Likewise, less energy = less particle motion = lower temp. In the metric system, temperature is measured in degrees Celsius (°C)• 0° C = freezing point of water

• 100° C = boiling point of water

Unit: Mass

[typical tool used = electronic balance]

• Mass is commonly used to describe the weight of an object. The basic unit of mass is a gram (g).

• 1 kilogram (kg) = 1,000 grams (g)• 1,000 milligrams (mg) = 1 gram

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Conversions-Metric to Metric

• Conversion between the different units within the metric system is accomplished by using the ‘Quick Conversion Line’ to move the decimal point the appropriate number of places in the appropriate direction.

milli1/1000

centi1/100

deci1/10

Unitmeterlitergram

deka10

hecto100

kilo1000

How can you remember this? Kids Having Doughnuts Usually Drink Chocolate Milk

Conversions-Metric to Metric

• In-class examples:• 58.9 kg = g

• 9,852,614 mm = km

• 852,614 mL = L

• .007621 kL = L

K H D U D C M

58900

9.852614

852.614

7.621

Conversions-Metric to English

• Example: convert 152 meters to yards.

• Solution:

€

152m x

1.094 yards

1 meter = 166.288 yards

what you are converting

an equivalency that features the unit you are converting from as the denominator - and your target unit as the numerator

the answer obtained by canceling the meter units - leaving yards - which was your target unit

Conversions-Metric to English

• Example: convert 152 meters to yards.

• Solution with Alternate method:

€

x

152m =

1.094 yards

1 meter

an equivalency that features the same units in the denominator and the numerator on both sides of the equation

the answer obtained by cross-multilying and solving for x

1 m • x = 1.094 yds • 152 m

x = 166.288 yds

1. Multiply numerators by denominators,2. Divide, if needed.

Conversions-Metric to English

• In class examples:This info will always be available to you (don’t need to memorize)

€

765.5cm x

1.0 in

2.54 cm =

1) 765.5 cm = _____ in

2.54 cm = 1 in, set up equivalency with in on TOP (what you are converting TO)

€

765.5cm x

1.0 in

2.54 cm = 301.4 in

Then do the math…

Conversions-Metric to English

• In class examples:This info will always be available to you (don’t need to memorize)

€

50kg x

2.20 lbs

1 kg =

2) 50 kg = _____ lbs

1 kg = 2.20 lbs, set up equivalency with lbs on TOP (what you are converting TO)

Then do the math…

€

50kg x

2.20 lbs

1 kg = 110 lbs