Measurement Units

Customary

* These items need not be memorized.

Length

inch (basic unit)

foot = 12 inches

yard = 3 feet (36 inches)

furlong = 220 yards (660 feet)

mile = 5280 feet ( 1760 yards ) ( 8 furlongs)

* nautical mile 1.1500779 mi. ( ~6076 ft. )

fathom = 6 feet

* rod = 5 1/2 yards

* chain = 22 yards = 4 rods = 1/10 furlong

Volume

Wet

teaspoon = 1/3 tablespoon

tablespoon = 1/2 ounce

ounce = (basic unit)

jigger = 2 ounces

gill = 2 jiggers (4 oz.)

cup = 8 ounces ( 2 gills )

pint = 2 cups ( 16 oz. )

quart = 2 pints (32 oz.)

*pottle = 2 quarts (64 oz.

gallon = 4 quarts (128 oz.)

* (231 cubic inches)

Dry

pint

quart = 2 pints

peck = 8 quarts

bushel = 4 pecks (2150.42 cubic in.)

* Barrel = 105 quarts (varries with material being measured)

Weight

Avoirdupois

dram = 27 & 11/32 grains

ounce = 16 drams (437.5 grains)

pound (lb.) = 16 ounces ( 7000 grains )

hundredweight (cwt.) = 100 pounds

ton = 2000 lbs. (20 cwt.)

* Troy

* ounce ( 480 grains)

* pound = 12 ounces ( 5760 grains )

The above interaction in systems results in the standard joke that an ounce of gold weighs more than an ounce of feathers but a pound of gold weighs less than a pound of feathers. Since gold is weighed in the troy system and feathers in the avoirdupois.

Area

Square foot 1 foot x 1 foot

Square Yard 1 yard x 1 yard

Square Mile 1 mile x 1 mile

Section a Square Mile

Township 36 Sections

acre = 160 square rods ( 43560 square feet) or (1/640 square mi.)

Temperature

Three Systems Fahrenheit, Celcius, and * Kelvin

The Fahrenheit system is one of the earlier. It was based on 0 being the freezing point for brine or salt water. Then 32 being the freezing point of fresh water. And 96 is an estimate for the usual body temperature. The difference 96-32 = 64 was deliberate since 64 is a power of 2 and the scale could be produced by bisection. The estimated temperature of boiling was set st 212 degrees. The estimate for body temp was off but the scale points for 32 and 212 were preserved.

The Celcius ( formerly Centigrade ) system is an outgrowth of the metric system and it's decimalization (as is our monetary system in the US). Zero is set at the freezing point of fresh water and 100 at the boiling point. The Kelvin system uses the same degree size as Celcius but sets the Zero at Absolute Zero or the point of minimum entropy or thermal motion. Zero Kelvin is -273.15 Celcius or -459.7 Fahrenheit.

While the Fahrenheit Celcius conversion is easy we will be more interested in developing a feeling for typical temperatures.

Metric

Legalized in the US in 1866.

Prefix Multipliers

Factor 10 Exp Name Abreviation
1/1000000000000 -15 femto f
1/1000000000 -12 pico p
1/1000000 -9 nano n
1/1000000 -6 micro µ, (mu)
1/1000 -3 milli m
1/100 -2 centi c
1/10 -1 deci d
1
10 1 deka da
100 2 hecto h
1000 3 kilo k
1000000 6 mega M
1000000000 9 giga G
1000000000000 12 tera T
1000000000000000 15 pita P
1000000000000000000 18 exa E
1000000000000000000000 21 zetta Z

These multipliers occur before the units or the abreviations of the units.

The custom is to not use a period with metric units as is done with customary units. Thus write cm but use in. for the customary units.

Length

m Meter

* (distance traveled by light in 1/299,732.458 seconds)

Volume

l Liter

( cubic decimeter) = (1 dm )3

Weight

g gram

( milliliter of water) ( cubic centimeter of water)

Also:

1 kg

( 1 liter of water )

Also:

T metric ton or long ton (1000 kg)

( cubic meter of water )

Area

a are

( square dekameter)

Usual use is hectare

( 100 m by 100 m ) for hectare

Common Values

Sizes for common situations. The comparisons are similar and are NOT exact conversions. They represent reasonable measurement errors and estimates to rounded values.

Temperature

Fahrenheit Celcius Situation Abreviation
    0   -17 Very cold
  32      0 Water freezes
  40    10 damage for sensitive plants
  68    20 room temperature
  95    35 hot
113    45 very hot
350  175 medium oven
Length

Traditional Metric Situation Abreviation
    1 yd.   1 m Nose to finger end
    5 mi.      8 km Across town
    400 mi.    600 km Houston -- Dallas
    5 in.    12 cm Pen
    30 in.    60 cm door width
    20 ft.    6 m Garage door
    0.004 in.  1 mm Very thin
Wet Volume

Traditional Metric Situation Abreviation
    quart   liter Medium bottle
    pint      250 ml Large drinking glass
    400 mi.    600 km Houston -- Dallas
Weight

Traditional Metric Situation Abreviation
    1.1 tin   1 ton Small car
    135 lb.      60 kg Small Adult
    2.5 lb.    1 kg Textbook