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Using Numbers in ScienceAND

Metric System

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Parts of a Measurement

1. The value (numerical portion)2. The unit (describes what units)3. The name of substance being measured

EX:1 teaspoon salt2 liters of pop

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The Metric System &

• Scientific Measurements made in metric units• Referred to as the International System or SI

units• Based on the decimal system• Related by powers of 10• Each type has a base unit• Use prefixes to refer to a unit larger or smaller

than the base by some power of 10

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SI (International System) unitsLength meter m

Mass kilogram kg

Temperature Kelvin K

Time second S

Volume Liter L

Centigrade or Celsius = ⁰C This is the unit we will use in lab for temperatures!

Prefixes for Metric Units <1

deci (d) = 1/10 = 0.1 centi (c) = 1/100 = 0.01 milli (m) = 1/1000 = 0.001decimilli (dm) 10-4 centimilli (cm) 10-5

micro (µ)10-6 = 1/100000 = 0.000001

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Prefixes for Metric Units >1

kilo (k) = 1000

hecto (h) = 100

deka (da) = 10

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kilo hecto deca Base Unit

deci centi milli micro

k h da gram (g) d c mm μ

1000 100 10 liter (L) 0.1 0.01 0.001 0.000001

103 102 101 meter (m) 10-1 10-2 10-3 10-4 10-5 10-6

Metric Unit Conversions

Millimeter

Could be the diameter of a straight pin

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Centimeter

1 inch = 2.54 centimeters

Which is about the length of a sugar cube

A paperclip could be about 2.54cm long

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Meter

Kilometer

Mass

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Mass

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Volume

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Volume

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Class Activity 1 – Understanding Metric UnitsPart A - Matching

A. LengthB. MassC. TemperatureD. TimeE. Volume (liquids)

Part B – select the best prefix

Class Activity – Part CWhat are the correct abbreviations?

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____ milligram ____ milliliter ____ liter _____centimeter

____ kilogram ____ millimeter ____ kilometer ____ gram

____ meter ____ millisecond ____ microgram _____ hectometer

____ micrometer ____ microliter

Part D

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Review Questions

1. What does the prefix "milli" mean?

A. millionth B. thousandthC. hundredth

2. A liter is a little more than a _______

A. pound B. gallon C. quart

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3. What is a good height for a basketball player?

A. 6 meters B. 2 meters C. 6 millimeters

4. Which is the longer distance to run ?

A. 50 metersB. 50 kilometersC. 50 miles

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5. Which value would be right for the mass of a

A. 17 mg B. 17 g C. 17 kg

6. Which value would be right for the mass of a

A. 460 mg B. 460 g C. 460 kg

What units would best be used to record the length, volume or mass

of these objects?