1. Measurement

2. Measurement Measurements have 2 parts: Example: 5cm
A number
A unit
Example: 5cm
Scientists (and we will) use the SI system
Système International d’unités

3. The SI units = METRIC
There are only 3 countries in the whole world using the ENGLISH SYSTEM of measurement
Liberia
Myanmar (formerly Burma)
THE UNITED STATES of AMERICA
Why is the metric system so much easier?
Most countries use it
It is based on powers of 10

4. Units There is always a BASE unit for every measurement
There can be prefixes added to the base to make it larger or smaller
Example: millisecond, kilogram

5. Base Units Length = meter (m) Mass = gram (g)
Volume = liter (L) or cubic centimeters (cm3)
Time = second (s)
** Prefixes multiply the BASE unit by a value of 10 **

6. PREFIX Symbol multiplier
Kilo k 1,000
hecto h 100
deka da 10
base: 1
deci d 0.1
centi c
milli m

7. King Henry Died Unfortunately Drinking Chocolate Milk

8. Unit Conversions
The metric system is so useful because we can convert from one unit to another EASILY
Write out the abbreviations in a horizontal row: K H D U D C M
Find the location of the original unit, then count the number of jumps and direction to the new unit
Re-write the number, then hold the pencil on the decimal point.
Move your pencil, making “egg crates”, the number of jumps in the correct direction- then fill in the empy crates with ZEROS
Re-write your final answer, including number and unit

9. Let’s try some!
Convert: 12 gram to kilograms hL to cL 5.22 seconds to milliseconds dm to cm How many centiliters are in 1 kiloliter?

10. Length Length = distance from one point to another
Length is measured with a METRIC RULER
The BASE unit = meter
Examples: centimeter (cm), millimeter (mm), decimeter (dm)

11. Mass Mass= the amount of matter in an object
Mass is measured with a balance
The BASE unit = gram
Examples: kilogram (kg), milligram (mg)

12. Volume= the amount of space something takes up
Solid Measurement
Liquid Measurement
The BASE unit = cm3
Use a formula to calculate for regular shapes
For irregular shapes use Water Displacement Method
The BASE unit = Liter
Use a GRADUATED CYLINDER to measure

13. Volume Direct Measurement Indirect Measurement
Use a ruler to measure and plug into formula
Example:
Volume of a cube =
length x width x height
Water displacement method
Fill a graduated cylinder with water- record volume
Carefully add object- record new volume of water
Subtract old volume from new volume = volume of object

14. In order for a measurement to be reliable…
It needs to be both ACCURATE and PRECISE
Accuracy = EXACT
Precision = multiple measurements close to each other

15. Scientific Notation Makes using large numbers easier
Write a number times a power of 10
Example:
3.0 x 108 = 300,000,000
Number must be between 1 and 10
Always there
The NUMBER of places and DIRECTION the decimal is moved

16. Scientific Notation
#’s less than 1 ( ) have a NEGATIVE exponent
#’s greater than 1 have a POSITIVE exponent

17. Try Some:
Expand:
4.2 x 104
3.359 x 10 -6
x 108

18. Try Some More…
Write in scientific notation:
870
0.245
75000