A number A unit Example 5 cm Scientists and we will use the SI system Système International dunités The SI units METRIC There are only 3 countries in the whole world using the ENGLISH SYSTEM of measurement ID: 930535
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Slide1
Measurement
Slide2Measurement
Measurements have 2 parts:
A
number
A
unit
Example:
5
cm
Scientists (and we will) use the SI system
Système
International
d’unités
Slide3The 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
Slide4Units
There is always a
BASE
unit for every measurement
There can be prefixes added to the base to make it larger or smaller
Example: milli
second
, kilogram
Slide5Base Units
Length = meter (m)
Mass = gram (g)
Volume = liter (L) or cubic centimeters (cm
3
)
Time = second (s)
** Prefixes multiply the BASE unit by a value of 10 **
Slide6Kilo k 1,000
hecto
h 100
deka
da
10
base: 1deci d 0.1centi c 0.01
milli
m 0.001
PREFIX
Symbol multiplier
Slide7K
ing
H
enry
D
ied
U
nfortunately
D
rinking
C
hocolate
M
ilk
Slide8Unit 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
Slide9Let’s try some!
Convert:
12 gram to kilograms
87.25
hL
to
cL
5.22 seconds to milliseconds99.99 dm to cm
How many centiliters are in 1 kiloliter?
Slide10Length
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)
Slide11Mass
Mass= the amount of matter in an object
Mass is measured with a balance
The BASE unit = gram
Examples: kilogram (kg), milligram (mg)
Slide12Volume
Solid
Measurement
The BASE unit = cm
3
Use a formula to calculate for regular shapes
For irregular shapes use Water Displacement Method
Liquid Measurement
The BASE unit = Liter
Use a GRADUATED CYLINDER to measure
Volume= the amount of space something takes up
Slide13Volume
Direct Measurement
Use a ruler to measure and plug into formula
Example:
Volume of a cube =
length x width x height
Indirect Measurement
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
Slide14In order for a measurement to be reliable…
It needs to be both ACCURATE and PRECISE
Accuracy
= EXACT
Precision
= multiple measurements close to each other
Slide15Scientific Notation
Makes using large numbers easier
Write a number times a power of 10
Example:
3.0
x 10
8
= 300,000,000
Number must be between 1 and 10
Always there
The NUMBER of places and DIRECTION the decimal is moved
Slide16Scientific Notation
#’s less than 1 (0.30400823) have a
NEGATIVE
exponent
#’s greater than 1 have a
POSITIVE
exponent
Slide17Try Some:
Expand:
4.2 x 10
4
3.359 x 10
-6
7.8112 x 10
8
Slide18Try Some More…
Write in scientific
notation:
870
0.0000789
0.245
75000