1. Nature of Science
Metric System-International System of Units
(SI)

2. Learning Targets: Use appropriate tools and equipment for measuring
Use the metric system for measuring
Use the “ladder method” and dimensional analysis to convert values between metric and English units

3. Merci Beaucoup!!!

4. The Metric System
Standardized system of measurement used by all scientists worldwide.
Based on units of 10
Similar to our monetary system:
10 cents = dime
100 cents = dollar
10 dimes = dollar

5. Why use the SI System?
In the U.S. we use the English or Standard System, most of the rest of the world uses the Metric or SI System.
Scientists use the SI System worldwide because:
Measurements are easily understood by all scientists
Measurements are easier to convert than the English system
The SI (International System of Units) system is the form of measurement typically used by scientists.

6. In the English system you have to remember so many units numbers . . .
12 inches in a foot
3 feet in a yard
5,280 feet in a mile
16 ounces in a pound
4 quarts to a gallon
In the SI System you only have to remember one number and a few basic units

7. Basic Types of Measurement
Length: measures distance between objects
Volume: measures the amount of space something takes up
Mass: measures the amount of matter in an object
Temperature: measures molecular movement
in an object

8. Measurement System Comparisons
BASIC UNIT
ABBREVIATION
LENGTH
Meter m
VOLUME
Liter L
TEMPERATURE
Celsius °C
MASS
Gram g
TIME
Second
s, sec
All Measurement systems have standards. Standards are exact quantities that everyone agrees to use as a basis of comparison.

9. 1 Liter
1 Gram
1 Meter

10. A Canook’s Rhyme
Thirty's warm,
twenty's nice;
ten's cold,
zero's ice

11. Weight vs. Mass Measure of the force of gravity on an object
Measure of amount of matter in an object NOT affected by gravity

12. Weight vs. Mass Weight and Mass are related, but NOT the same.
Weight can change depending on location
Mass is constant regardless of location
The greater the mass, the larger the pull of gravity.
The larger the pull of gravity, the greater the weight

13. Metric System Prefixes
Kilo
1000
Hecto
100
Deca 10
Base Unit
g, m , L 1
Deci .1
1/10
Centi
.01 1/100
Milli
.001 1/1000
The Base Unit is the determined by the type of measurement being made. (mass, volume, or length)
The same prefixes are used regardless of the the measurement type being made length, mass, or volume.

14. Hecto Increase to Basic Unit Deca Basic Unit (g,m,L) Deci
Metric Prefixes
Kilo
Hecto Increase to Basic Unit
Deca
Basic Unit (g,m,L)
Deci
Centi Decrease to Basic Unit
Milli

15. µ - micro- one millionth
ex. Micrometer or micron
n nano one billionth

16. Abbrev. Word Meaning mm millimeter one thousandth meter cg kL cm mL mg km kg

17. Abbrev. Word Meaning mm millimeter .001 meter (thousandth) cg centigram .01 gram (hundredth) kL kiloliter 1000 liters cm centimeter .01 meter (hundredth) mL milliliter .001 meter (thousandth) mg milligram .001 gram (thousandth) km kilometer 1000 meters kg kilogram 1000 grams

18. “Ladder Method” Used for metric to metric conversions
Conversions are done by moving the decimal point.
Larger to smaller unit:
Move decimal point to the right
Smaller to larger unit:
Move decimal point to the left

20. The Metric System is used for everyday life in most countries except the United States, Liberia and Myanmar

21. Dimensional Analysis/ Factor Label Method
Method we will use to convert English – Metric units. When does this skill come in handy?

22. Dimensional Analysis Determine the equality relationship between units
ex cm = 1 inch
Write the relationship between the units as a fraction with the desired unit in the numerator (top) and the unit you have in the denominator (down). This is the conversion factor .
2. 54 cm Numerator
1 inch Denominator
Multiply the value you have by the conversion factor - it’s like multiplying by one.
10 inches x cm
1 inch
Cancel out the units , multiply, solve
10 inches x cm = cm

23. Choosing Conversion Factors
How many feet are in 144 inches?
Determine the relation between feet and inches
12 inches OR foot___
1 foot inches
Choose the conversion factor with the desired
unit in the numerator

24. Choosing Conversion Factors
How many feet are in 144 inches?
Determine the relation between feet and inches
12 inches OR foot
1 foot inches
Choose the conversion factor with the desired
unit in the numerator

25. Practice: Choose the appropriate conversion factor.
Inches to feet
Minutes to hours
Meters to centimeters

26. Practice: Choose the appropriate conversion factor.
Inches to feet
Minutes to hours
Meters to centimeters

27. Example #1 36 eggs = ? Dozen Determine equality 12 eggs = 1 dozen
Determine Conversion factor
12 eggs or dozen
1 dozen eggs

28. Example #1 36 eggs = ? Dozen Determine equality 12 eggs = 1 dozen
Determine Conversion factor
12 eggs or dozen
1 dozen eggs

29. Example #1 36 eggs = ? Dozen Conversion factor: 1 dozen 12 eggs
36 eggs x 1 dozen = x 1 dozen = 3 dozen
12 eggs

30. Example #2 10 cm = ___?___ inches Choose conversion factor:
2.54 cm or inch__
1 inch cm
Although these are both equivalent, choose the one with the desired unit in the numerator (top)

31. Example #2 10 cm x 1 inch__ = _________ 2.54 cm
10 cm x 1 inch__ = 10 x 1 inch = in
2.54 cm

32. Convert 8 yards to feet…
Determine the equality relationship between units
Make a decision: What conversion factor will you use?
Set up the problem: Multiply the measurement by the conversion factor.
Solve the problem: Perform the multiplication

33. Things to Remember All measurements need a number and a unit!
Basic units of Measurement (meter, liter, gram)
Metric prefixes and values
How to convert units

34. Measurement Review Measurements need a number and a unit!
Basic units of Measurement (meter, liter, gram) and prefixes
How to convert metric units
Be able to make basic measurements of volume, length, and mass
Definition of density and how to figure it out.
Vocabulary words

35. Metric Measurement: Length
Length is the distance between two points.
Does not matter if it is width, height, depth, etc. All are length measurements.
The basic unit of length in the SI System is the meter.
The meter is about the length of the English yard (3 feet).
Area is a variation of a length measurement.
Area is length x width.
Expressed in units2 (m2, cm2, mm2 etc.)

36. Metric Measurement: Mass
Mass is a measurement of the amount of matter in an object.
Basic unit of mass is the gram. There are 454 grams in one pound.
Weight and mass are related, but NOT the same.
Weight is the pull of gravity on an object
The greater the mass, the larger the pull of gravity.

37. (L)ength x (W)idth x (H)eight
Metric Measurement: Volume
Volume is a measurement of the amount of space something takes up.
The basic unit used for volume is the liter. This unit is used for the volumes of liquids.
Volumes of solids are figured using this formula:
(L)ength x (W)idth x (H)eight
cm x cm x cm = cm3
Objects without a definite length, width or height (a rock for example), can use water displacement to determine volume NOTE: 1 ml = 1 cm3

38. Metric Measurement: Temperature
Temperature is a measure of the kinetic energy of the atoms in an object.
Temperature is measured with a thermometer and measured in Celsius or Kelvin.
Celsius ranges from 0 (freezing) to 100 (boiling).
The Kelvin scale begins at absolute zero, or 0 K. At 0 Kelvin no more heat can be removed from an object.
To convert to Kelvin you add 273 degrees to the Celsius reading.
Freezing in Kelvin is 273 K, boiling is 373 K.

39. Which is heavier . . . The formula for density is:
Density is how much matter is in something (mass), compared to the amount of space it takes up (volume).
Which is heavier . . .
A kilogram of feathers or a kilogram of lead?
They are both one kilogram so they weight the same, but it takes more feathers than lead to equal one kilogram!
The formula for density is:
Mass (grams)
divided by
Volume (cm3)
So the unit for density is g / cm3
Every substance has a density, and that density always remains the same.
Density can be used to figure out what an unknown substance is.
The density of water is 1 g / cm3
Which one takes up more space (volume)?
We say the lead is more dense than the feathers.