Title: Standards of Measurement
1Standards of Measurement
- an exact quantity that people agree to use for
comparing measurements
standard
Why do we need standards?
- without them, we could never accurately
communicate about measurements
2Units of Measurement
- a precise measurement used to describe other
measurements of the same type
unit
Why do we need units?
- they must be used in order for people to
understand your measurements
3SI System of Measurement
- in 1960, an international group of scientists
agreed upon a system of standards and units
- it was called Le Systeme Internationale
dUnites (or International System of Units)
abbreviated SI
4why SI?
advantages of SI
1. all measurements contain steps of 10
2. it is used all over the world
5SI Base Units
base unit
- the basic unit for all the measurements of a
certain type
6Using SI Measurements
- often, the SI base units are too large or too
small to make the measurements we need
example it would take forever to measure the
distance to Carlin in meters!!
example most insects weigh much less than 1
kilogram.
7SI Prefixes
- for very large or small measurements, we use
the steps of 10 that go with our base units
- there are prefixes that go along with the most
common steps of 10, and they are placed with the
base unit
8example
The SI distance from Carlin to Elko is 37,000
meters.
- that is the same as saying 37 x 1,000 meters
- 1,000 can be represented with the prefix kilo
- therefore, the distance becomes 37 kilometers
(37km)
9common prefixes
- since all SI measurements are based on steps of
10, these prefixes can be used for all types of
measurements
10(No Transcript)
11choosing a unit
1. decide what type of measurement youre making
(is it length, mass, time, etc.?)
2. decide what base unit you are going to use
(is it meters, kilograms, etc.?)
3. decide if the base unit is too large, too
small, or just right for the measurement you need
to make
12choosing a unit
4. if the base unit is too large or small, add a
prefix to make it the right size
- if the unit is too small, add a large prefix
(like kilo)
- if the unit is too large, add a small prefix
(like centi, milli, etc.)