Units of Measurement Science 9 September 2016

Vocab Unit – a standard of measurement in which other measurements are expressed. English System (United States Customary System) – system of measurement used in the US, includes inches, gallons, pounds, miles, etc. Metric System – system of measurement used in countries other than the US and by the scientific community; units are organized by factors of 10. Prefix – element placed at the beginning of a word that changes the meaning of the word; in the metric system, it indicates a unit smaller of larger than the basic unit by factors of 10.

Why is measurement important? Use it in daily life Cooking Construction Decorating a room Driving Communication Need to be able to communicate measurements and distances to other people

Measurement & Physics Physicists try to find relationships between the quantities they measure  use units of measurement to do this Measure the very largest and smallest things in the universe Smallest: mass of an electron = 0.000000911 yg Largest: light years (distances between stars and galaxies

Units of Measurement Distance Mass Time Area/Volume Temperature inch milligram hours in^2, in^3 Fahrenheit meter ounces seconds m^2, m^3 Celsius mile pounds days Liters Kelvin feet gram months Gallon centimeter kilogram years Quart millimeter tons minutes Pint

How to use a ruler: 1. Determine if you are measuring in centimeters or inches and find that unit’s side of the ruler. centimeters inches

How to use a ruler “0” mark Place the “0” mark at one end of the object you are measuring. “0” mark

How to Use a Ruler Record the ruler marking that falls at the other end of the object For INCHES: - Each dash after a whole inch is 1/16 of an inch For CENTIMETERS: - Each dash after a whole centimeter is 1/10 of a centimeter

Measurement Lab

Relative Size Unit Relative Size Examples Inches 1 in Photo size, body parts Feet 1 ft = 12 in Height of people, room size Yard 1 yd= 3 ft Football field Meters 1 m ~ 1 yd Height of people, track length Kilometers 1km = 1000m Car travels, between cities Centimeters 1 cm = 0.01 m Paper, small machine parts, body parts Millimeters 1 mm = 0.001 m Coins

Two Main Systems of Measurement United States Customary System (USCS) System International (SI)- Metric System

USCS Used in the U.S. and Burma Distance: inch (in), foot (ft), yard (yd), mile (mi) Mass: pound (lb) Time: second (sec) Temperature: degrees Fahrenheit (F)

Metric System Used by all other countries and the scientific community Units that are larger or smaller units than the basic units are defined in multiples of 10 Basic Units Distance: meter (m) Mass: gram (g) Time: second (s) Temperature: degrees Celsius Volume: Litre (L)

Start here with metric conversion pre-test

Metric System: Prefixes Adding a prefix to a basic metric unit increases or decreases the unit size by a factor of 10 Prefixes are always added to the beginning of Metric basic units For example, centimeter (cm) milliliter (ml) kilogram (kg)

Metric Prefixes Prefix Symbol Relation to Basic Unit milli- m 1000 mm = 1 m centi- c 100 cm = 1 m deci- d 10 dm = 1 m deka- da 1 dam = 10 m hecto- h 1 hm = 100m kilo- k 1 km = 1000 m

Conversion Hints Staircase Method

Rules to using the Staircase Method of conversion Find the unit on the staircase where you are STARTING. ex. Convert 5 m = ________ cm You are starting at m. 2. Count up or down the stairs ending on the unit you need to convert to. ex. 5 m = ________ cm You need to convert to cm.

3. If you counted UP the stairs, move the decimal point LEFT. 4 3. If you counted UP the stairs, move the decimal point LEFT. 4. If you counted DOWN the stairs, move the decimal point RIGHT. ex. 5 m = ________ cm

5 m = ______ cm Move decimal 2 places to the right. 5 m = 500 cm

Convert: 116 kg = _______________ g Start at “kilo” and find “gram” (base). Count steps down…3 Move decimal 3 spots to the right 116 kg = 116,000 g

Convert: 5.468 hL = ____________ cL Start at “hecto” and find “centi” Count steps from h to c = 4 down Move decimal 4 spots to the right 5.468 hL = 54,680 cL

Convert: 9,436 mm = _____________ m Start at “milli” and find “meter” (base) Count steps from m to M = 3 steps up Move decimal 3 spots to the left 9,436 mm = 9.436 m

Now, do the pre-test again knowing the staircase method of conversions.

PRACTICE!! You will get a sheet to practice conversions. Use the staircase method (it is the easiest!) Do not be afraid to ask for help.