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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?