1. Metric System

2. “Inch by inch, life’s a cinch.
Yard by yard, life is hard.”
author unknown

3. Measurement Systems: English – only used in the United States
Metric – used all over the world
(International System of Units – S.I.)

5. Most Common Base Units
Meter – measures length(distance between 2 points)
Gram – measures mass (amount of matter in an object) kg
Liter – measures liquid volume(amount of space an object takes up)
Kelvin, Celsius – measures temperature

6. Prefixes Added to Base Units:
Kilo (1000) – k
Hecto (100)– h
Deka (10)- dk
Deci(1/10)– d
Centi(1/100)– c
Milli(1/1000)–m

7. Conversions: Base K h dk Liter d c m Gram Meter
King Henry Died By Drinking Chocolate Milk

8. Example: K h dk Liter d c m Gram Meter

9. Instruments: Length – metric ruler, meter stick
Mass – triple beam balance
Volume (liquid) – graduated cylinder
Volume (regular solid) –metric ruler
Volume (irregular solid) – graduated cylinder
Temperature – thermometer

10. Formulas: Volume of a solid - length x width x height unit = cm3
Temperature:
0 F = (1.8 x 0 C)
0 F = (9/5 x 0 C) + 32
0C = ( 0 F )
0C = 5/9 ( 0 F )
? 0 C = K – 273
? K = 0 C

11. Making Measurements:
“Only those who have the patience to do simple things perfectly will acquire the skill to do difficult things easily.”
Johann von Schiller

12. Measurements in Science:
In Science, we want measurements to be both accurate and precise.
What is the difference between accurate and precise?

13. Accurate (accuracy)
capable of providing a correct reading or measurement.
correctly reflects the size of the thing being measured.
refers to how closely a measured value agrees with the correct value.

14. Precise(precision) Repeatable Reliable
getting the same measurement each
time.
refers to how closely individual measurements agree with each other.

15. Examples: The Forecast is between 40 and 60 degrees today.
The actual reading turns out to be 53.
Thus, the forecast was accurate, but not very precise.

16. Examples: The forecast is 52.47 degrees at 4 PM.
It turns out to be 61 degrees.
This forecast was very precise, but completely inaccurate.

17. Neither accurate nor precise
random

18. Precise,
but not accurate

19. Accurate but not precise
Average is center of
Bull’s eye.

20. Accurate and
Precise

21. Emma: 5.0 cm
Group 1: Group2: Group3:
Which group is accurate?
Which group is precise?
Which group is accurate and precise

22. Significant Figures (digits):
Tell us how precise a measurement is.
The significant figures in a measurement include all the digits that can be known precisely plus a last digit that is an estimate.

23. Rules for Significant Figures:
Any non zero digits are significant.
example – 4.5 (2 SF)
Any zeros between numbers are significant.
example – 10.5 (3 SF)
Zeros to the left of the 1st non-zero digit are NOT significant.
example – (3 SF)

24. More Rules: 4. Final zeros after the decimal are significant.
example – 1.00 (3 SF)
5. Zeros to the right of the last non zero digit without a decimal point are not significant.
example – 123,000 (3SF)

25. If you like the Atlantic Pacific rule – check out the ppt entitled Significant Figures