Measurement
TWO SYSTEMS
METRIC
Used in science class and
around the world
Can multiply by 10, 100,
1000, etc… to go from one
unit to another
STANDARD
Used in America
Has uneven conversion
factors (probably need to use
a chart)
Common units:
Feet, inches, yards for
distance
Ounces, cups, pints, gallons
for liquid
Common base units:
Meters for distance
Liters for liquid
Pounds for weight
Grams for mass
Fahrenheit for temperature
Newtons for weight
Celsius for temperature
Common prefixes we will see
in metric system:
CentiHectoMilliNanoKilo-
CONVERSIONS WE SHOULD KNOW:
To go from milli- to another unit:
From milli- to centi- divide by 10
From milli- to a base unit (grams, liters, etc…) divide by 1000
To go from centi- to another unit:
From centi - to milli- mutiply by 10
From centi-to base unit (grams, liters, etc…) divide by 100
To go from kilo- to another unit:
From kilo to base unit (grams, liters, etc…) multiple by 1000
From a base unit (grams, liters, etc…) to centi-, milli-, or kilo-:
From base unit to milli-, multiply by 1000
From base unit to centi -, multiply by 100
From base unit to kilo-, divide by 1000
LENGTH
Distance from Point A to Point B
Can be used to find volume of a square or rectangle
Find the length, width, and height of the object
Multiply them together (L x W x H)- they can be
interchangeable
Make sure your units are correct (cubed)
For example:
4 cm x 7 cm x 5cm =140 cm3
Volume
Boxes and rectangles as described on the previous
slide
Irregular objects (round, bumpy, triangular, etc…)
Water displacement method:
Fill graduated cylinder with a volume of liquid (lets say 30 ml)
Drop a ring into graduated cylinder and observe how far the water
rose (lets say 70 ml)
Subtract the starting volume (30 ml) from the ending volume (70 ml)
and it will tell you the object’s volume. In this case 40 ml.
Because it’s a solid, you need units to represent that.
1 ml= 1 cm3, so if I have 40 ml this is 40 cm3
Remember you need to read the meniscus (or curved line of water)
for an accurate reading
To read the meniscus, you want to be eye
level to the container and take the reading
at the bottom of the curve
Weight
Measure of how much gravity acts on an object
We use pounds everyday, however in science we
use Newtons
This will change based on where you go in the
universe
Because each planet or planetary body has it’s own
gravitational force
So if you go somewhere with more gravity, you will weigh more
If you go somewhere with less gravity, you will weigh less
Use a scale to measure
MASS
Measure of how much stuff is in an object
We use grams
This will not change based on where you
go in the universe
Because unless you lose part of yourself your mass will
not change
So if you go somewhere with more gravity, you will
have the same mass
If you go somewhere with less gravity, you will have the
same mass
Use a balance to measure
FUN FACT: On Earth, mass
and weight are used
interchangeably in
everyday life
ACCURACY and PRECISION
Accuracy:
How close you are to the actual measurement
So if a book has a length of 15 centimeters, it is how many times you
ARE CLOSE TO 15 cm.
Precision:
How many times you receive same result in your data
How many times you get the same result with a piece of
equipment.
So if you receive 15 cm, 5 times, you have some precision to your
measurement
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