1. SI (Système International d’unités)
Metric System

2. Introduction The thermometer says 39°C. Your school is 2 km away.
Do you need a warm jacket or your shorts
Your school is 2 km away.
Do you need a ride or can you walk?
A box has a mass of 500 grams.
Can you lift this by yourself or do you need help?
Milk comes in a 2 liter container.
Can you share with your friends, or do you only have enough for yourself?

3. Measurement History
Since the beginning of time people have been measuring
Earliest recorded measurements involved length
Egypt, 3000 BC
Cubit
Palm
Digit

4. Length History Length units based on human body
Hand = width of human hand
Span = tip of pinky to tip of thumb
Foot = human foot
Cubit = tip of middle finger to elbow
Yard = tip of nose to thumb
Fathom = finger tip – finger tip of outstretched arms
Mile = “mille passe” = 1000 double paces

5. Volume History Volume originally measured by heaps or handfuls
Gallon = container that held 10 pounds of water
Quarts = ¼ of gallon

6. Mass History Mass originally measured by stones or seeds
Grain = based on number of seeds
Carat = based on “carob” seed
Stones = based on stones
Pound = money value once based on weight
English still use “pound” for currency
Ounce = romans divided pound into 12 units “unciae”
Later divided into 16 parts

7. So What’s the Problem?
Problems arose with accuracy, consistency, fairness
All feet, hands, paces aren’t the same
All handfuls and heaps aren’t the same
Different countries had different measurements
Greeks divided their foot into 16 units
Romans divided their foot into 12 units
Inch = Width of thumb
English used 3 barleycorns (seeds) to measure inch

8. So What’s the Answer?
Problems arose with accuracy, consistency, fairness
Standards were established
Standard: Agreed upon measurements that stay the same wherever you go
Systems
System: measurements that are all related
Customary System – based on body
Metric system – based on the Earth
Most widely accepted standards in world

9. What is the metric system?
Created in France 1793
Scientists based the system on a meter
Meter means “measure”
Distance from equator to North Pole /10,000,000
Used all over the world
US is only major country not to use
E.C. What are the only other two countries not to use metric system?
Based on 10s

10. Why the metric system? Scientists created and use the metric system
Science occurs all over the world – not just in USA
Scientists need to speak the same “language” when it comes to measurements
We’re in science class
The entire Earth (almost) uses the metric system
(The United States and two others)
Business and trade uses metric system
Especially if they interact with foreign markets

11. Quiz Length: Volume: How many inches in a foot
How many feet in a yard?
How many yards in a mile?
How many inches in a mile?
Volume:
How many teaspoons in a tablespoon?
How many tablespoons in a cup?
How many cups in a gallon?

12. Quiz (continued) Mass: Temperature: Extra Credit:
How many ounces in a pound?
How many pounds in a ton?
Temperature:
What is the freezing point of water?
What is the boiling point of water?
Extra Credit:
What is a common equivalent for the following: (Choose 4)
Fathom?
Chain?
Rod?
Furlong?
League?
Peck?

13. Extra Credit Extra Credit:
What is a common equivalent for the following: (Choose 4)
Fathom?
Chain?
Rod?
Furlong?
League?
Peck?

14. Race??? SI (Metric) Customary (American)
1.5 m 2.75 m m m
1 1/2 ft 2 3/4 ft 3 1/3 ft + 4 5/8 ft

15. And the Winner Is??? SI (Metric) Customary (American)
m 2.75 m m m 2
1 1/2 ft = /24
2 3/4 ft = /24
3 1/3 ft = /24
/8 ft = /24
(53/24 = 2 5/24) /24
( /24 = /24)
/24

16. Easier? The metric system is easier to use than our system
Only one base unit for each measurement
Prefixes help with very large/small measurements
Based on 10’s
Decimals not fractions
Faster
Very easy to add/subtract/multiply/divide
Changing prefixes; just move decimal

17. Comparison SI (Metric System) Units from Earth 1 unit with prefixes
Customary (American System )
Units from Earth
1 unit with prefixes
Based on 10s
Decimals
Faster
Units from body
Many units
Based on 2s, 3s, 4s, 8s, 12s, 16s, 36s, etc.
Fractions
Slower
Metric units from distance of equator to North pole / 10,000,000
American units from the foot, width of finger, outstretched arms, double paces, etc.
Meter, Liter, Gram
Inches, Feet, Yards, Miles (Rod, Furlongs, Fathoms, Chains, etc.) Ounces, teaspoons, Tablespoons, Pints, Quarts, Cups, Gallons, Barrels, (hogs head, gil, dram, jigger) Ounces, Pound, Ton, (grain, dram)
Everything is based on 10 – How many ____ in a ____?
Inches in a foot? Feet in a yard? Feet in a mile? Yards in a mile? Ounces in a cup? Cups in a quart? Quarts in a gallon? Ounces in a pound? Pounds in a ton?
Because it is based on 10s – you use decimals (tenths, hundredths, etc)
American system is not based on 10s and we usually use fractions, 17/64, ½, ¼, etc
Because you use decimals much faster – race (

18. Prefixes (mnemonic device)K H Da M D C

19. Prefixes K H Da M D C
King
Harry
Decked My
Dad’s
Creepy
Monster

20. Length Base unit – meter Smaller – decimeter Smaller yet – centimeter
Meter stick or metric ruler
Smaller – decimeter
10 decimeters = 1 meter
1 decimeter (10-20)(40-50)
Smaller yet – centimeter
10 centimeters = 1 decimeter
1 centimeter (11-12)(47-48)
Smallest – millimeter
10 millimeters = 1 centimeter
1 millimeter (distance between tiny tick marks)

21. Where do decimals come in?
In between whole numbers
Between 4 and 5 cm
Write “4.”
Count the smaller unit (3 little tick marks)
Write the number after the decimal 4.3 cm

22. Changing Prefixes Based on 10s Example 1 Example 2 11.8 cm = ? mm
11.8 cm x 10 mm = 11.8 x 10 = 118 mm
1 cm
Example 2
4.65 m = ? mm
4.65 x 10 x 10 x 10 = 4.65 x 1000 = 4650

23. Changing Prefixes Based on 10s Example 1 Example 2 11.8 cm = ? m
11.8 cm x 1 dm x 1 m = = m
10 cm dm
Example 2
4.65 m = ? km

24. Additional Examples

25. Length Summary Length: distance between two points
Instrument: metric ruler / meter stick
Base unit: meter (m)
Accuracy:
Start at the “0”
Count accurately
Meter sticks end to end
Measure in a straight line

26. Volume Summary Volume: amount of space an object takes up
Instrument: graduated cylinder
Base unit: liter (L)
1 cm3 = 1 mL
Accuracy:
Know what you are counting by 0.5s, 1’s, 5s,
Keep graduated cylinder on flat surface
Measure to bottom of meniscus
Read meniscus at eye level

27. Volume by Difference Measure volume of water Add object to water
Easy to use number
Add object to water
Measure volume of water and object
Subtract beginning volume from ending volume

28. Mass Summary Mass: amount of matter in an object
Instrument: triple beam balance
Base unit: gram
1 cm3 water = 1 mL = 1 gram
1 L = 1 kg
Accuracy:
“Zero” triple beam balance before measuring
Carefully set object on pan
Keep triple beam balance on flat surface

29. “Zero” Triple Beam Balance
Clear off pan
Move all riders to “0”
Turn tare knob if pointer isn’t at “0”

30. Mass by Difference Find mass of an object Change the object
Add to it
Take away from it
Find the mass of the changed object
Subtract smaller mass from larger mass

31. Temperature Summary
Temperature: amount of thermal (heat )energy in object
Instrument: thermometer
Base unit: degree Celsius (°C)
Accuracy:
Know what you are counting by
Below “0” temperatures are “-”
Keep thermometer in middle of substance

32. Graph Summary X-axis: horizontal axis (bottom)
Plot independent variable
Independent variable: variable that you change / test
Y-axis: vertical axis (side)
Plot dependent variable on
Dependent variable: variable that you observe/measure

33. Graph Summary (continued)
Set-up your graph
Label your axes with variables and units
Label your axes with numbers
Determine maximum value for each variable
Count number of lines across & up and down
Choose an easy number to count by (1s, 2s, 5s, 10s)
Label only a few of the lines
Plot points (across, then up)
Connect dots with line (trend line)
Add title (include both variables)

34. Safety Glassware: Triple beam balances: Substances:
Carry with two hands
Set it down carefully
Keep it in the middle of table
Triple beam balances:
Keep it in the middle of the table
Substances:
Don’t eat or drink (unless given permission)