1. The Methods of Science Standards of Measurement
To have accurate measurements, you must have a standard, which is an exact quantity that people agree to use for comparison
The system of measurements that is universally accepted and understood by scientists is the International System of Units (SI)

2. The Methods of Science SI Base Units Quantity Measured Unit Symbol
Length
Mass
Time
Electric Current
Temperature
Amount of Substance
Intensity of LIght

3. The Methods of Science SI Base Units Quantity Measured Unit Symbol
Length
meter m
Mass
Time
Electric Current
Temperature
Amount of Substance
Intensity of LIght

4. The Methods of Science SI Base Units Quantity Measured Unit Symbol
Length
meter m
Mass
gram g
Time
Electric Current
Temperature
Amount of Substance
Intensity of LIght

5. The Methods of Science SI Base Units Quantity Measured Unit Symbol
Length
meter m
Mass
gram g
Time
second s
Electric Current
Temperature
Amount of Substance
Intensity of LIght

6. The Methods of Science SI Base Units Quantity Measured Unit Symbol
Length
meter m
Mass
gram g
Time
second s
Electric Current
ampere A
Temperature
Amount of Substance
Intensity of LIght

7. The Methods of Science SI Base Units Quantity Measured Unit Symbol
Length
meter m
Mass
gram g
Time
second s
Electric Current
ampere A
Temperature
kelvin K
Amount of Substance
Intensity of LIght

8. The Methods of Science SI Base Units Quantity Measured Unit Symbol
Length
meter m
Mass
gram g
Time
second s
Electric Current
ampere A
Temperature
kelvin K
Amount of Substance
mole
mol
Intensity of LIght

9. The Methods of Science SI Base Units Quantity Measured Unit Symbol
Length
meter m
Mass
gram g
Time
second s
Electric Current
ampere A
Temperature
kelvin K
Amount of Substance
mole
mol
Intensity of LIght
candela cd

10. The Methods of Science Measuring Time
time – the interval between two events
the SI unit for time is the second

11. The Methods of Science Measuring Temperature
temperature – a measure of how hot or cold something is
the SI unit for temperature is the kelvin
to change Celsius to Kelvin, K = C + 273
to change Kelvin to Celsius, C = K – 273

12. The Methods of Science
Temperature

13. The Methods of Science
Measuring Distance – also referred to as measuring length
the units used to measure length depend on what is being measured
example: meters may be used to measure the length of a field
example: micrometers may be used to measure the length of a bacteria

14. volume = length x width x height
The Methods of Science
Measuring Volume
volume – the amount of space that an object occupies
solids - to measure the volume of a solid object, you multiply the length, width, and height
units for volumes of solids will almost always be cubed (ex. m3, cm3, and mm3)
volume = length x width x height

15. The Methods of Science
volume – the amount of space that an object occupies
liquids - to measure the volume of a liquid, you measure the capacity of the container that holds the liquid
the units for measuring volumes of liquids will usually be in liters or milliliters
changing from volumes of solids to volumes of liquid
1 L = 1dm & mL = 1 cm3

16. The Methods of Science Measuring Matter
mass – a measurement of the quantity of matter in an object
mass is usually measured in grams (g) or kilograms (kg)

17. The Methods of Science Measuring Matter
density – the mass per unit volume of a material
density can be thought of as how “compact” something is
you find density by taking the mass of an object and dividing by its volume

18. The Methods of Science
density – the mass per unit volume of a material
Example: What is the density of a metal that has a mass of 158g and a volume of 20 ml?
158g
D =
=7.9 g/ml
20 ml

19. The Methods of Science 1) mass= 9.9g; Volume= 25 mL; Density =?
2) mass=?; Volume= 30mL; Density= 80 g/mL
3) mass= 45g; Volume=?; Density= 8.00 g/mL

20. The Methods of Science
The SI system is easy to use because it uses SI prefixes which is based on multiples of 10
example: milli means one-thousandth (0.001 meters)

21. The Methods of Science Kilo- Hecta- Deca- Base unit Deci- Centi-
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo-
Hecta-
Deca-
Base unit
Deci-
Centi-
Milli-

22. The Methods of Science Kilo- k 1,000 Hecto- Deca- Base unit Deci-
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo- k
1,000
Hecto-
Deca-
Base unit
Deci-
Centi-
Milli-

23. The Methods of Science Kilo- k 1,000 Hecto- h 100 Deca- Base unit
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo- k
1,000
Hecto- h
100
Deca-
Base unit
Deci-
Centi-
Milli-

24. The Methods of Science Kilo- k 1,000 Hecto- h 100 Deca- da 10
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo- k
1,000
Hecto- h
100
Deca- da 10
Base unit
Deci-
Centi-
Milli-

25. The Methods of Science Kilo- k 1,000 Hecto- h 100 Deca- da 10
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo- k
1,000
Hecto- h
100
Deca- da 10
Base unit 1
Deci-
Centi-
Milli-

26. The Methods of Science Kilo- k 1,000 Hecto- h 100 Deca- da 10
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo- k
1,000
Hecto- h
100
Deca- da 10
Base unit 1
Deci- d
0.1
Centi-
Milli-

27. The Methods of Science Kilo- k 1,000 Hecto- h 100 Deca- da 10
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo- k
1,000
Hecto- h
100
Deca- da 10
Base unit 1
Deci- d
0.1
Centi- c
0.01
Milli-

28. The Methods of Science Kilo- k 1,000 Hecto- h 100 Deca- da 10
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo- k
1,000
Hecto- h
100
Deca- da 10
Base unit 1
Deci- d
0.1
Centi- c
0.01
Milli- m
0.001

29. The Methods of Science Metric to Metric Unit Conversions Units
Sometimes quantities need to be converted from one unit to another. How do we do that?
Example: You have a length of rope that measures .7 dam. How long is that rope in dm?
Example: You live mm away from school. How many km is this?

30. The Methods of Science
Kilo
(k)
1000x
Hector
(h)
100x
Deka
(da)
10x
Centi
(c)
1/100
Milli
(m)
1/1000
Deci
(d)
1/10
BASIC UNIT
King
Henry
Doesn’t
Usually
Drink
Chocolate
Milk
To convert to a smaller unit, move decimal point to the right
To convert to a larger unit, move decimal point to the left

31. The Methods of Science Converting Between English and Metric Units
Sometimes quantities are measured using different units and conversion factors are used to change from one unit to another.
To properly convert units there are 5 rules that need to be followed when converting between the English and Metric system.

32. The Methods of Science Rules for Converting Between Units
1. Identify your “given” and “find”
the information given to you in the problem and the units you need to convert these to
2. Put the “given” in the top left corner of your railroad tracks
The units on the top and bottom of the railroad track need to be the same so that your units cancel out.
4. Use order of operations to solve for your final answer
5. Double check that you cancelled out all units correctly.
Given

33. The Methods of Science Converting Between Si Units
Sometimes quantities are measured using different units and conversion factors are used to change from one unit to another.
Example: You have a length of rope that measures 3,075 mm. How long is it in feet (ft)?

34. The Methods of Science Converting Between Si Units
Example: You have a length of rope that measures 3,075 mm. How long is it in feet (ft)?
Given: 3,075 mm
Find: ? ft ft
3,075 mm =
10.09 ft
1 mm

35. The Methods of Science Converting Between Si Units
Example: You travel a distance of 5.5 km. How far did you travel in miles (mi)?

36. The Methods of Science Converting Between Units
Example: You are counting down the days until spring break, which is 21 days away. How many seconds away is this?

37. The Methods of Science Uncertainty in Measurements Accuracy
The closeness of a measurement to the actual value of what is being measured.
Example: In throwing darts, you aim at the bulls eye and hit the bulls eye
Example: You measure the mass of an object three times and obtain values of 35g, 36g, and 35g when the actual mass is 34.5g.

38. The Methods of Science Uncertainty in Measurements Precision
The reproducibility of a set of measurements taken under the same conditions. This describes how closely grouped your data points are.
Example: In throwing darts, all three darts hit the 20.
Example: You measure the mass of an object three times and obtain values of 35g, 36g, and 35g when the actual mass is 48.5g.

39. The Methods of Science