System of Measurement

• English – standard measurement in the United States, now called U.S. Customary System– Uses, inch, foot, yard, rod and mile as units– 12 inches in a foot– 3 feet in a yard– 16 ½ feet in a rod– 5,280 foot in a mile

customary measurement system

A measurement system that measures length in inches, feet, yards, and miles

capacity in fluid ounces cups, pints,

quarts, and gallons

weight in ounces, pounds, and tons

and temperature in degrees Fahrenheit

Miles yards feet inches 1 = 1760 = 5280 = 63360

1 = 3 = 36 1 = 12

Gallons quarts pints cups Fl oz 1 = 4 = 8 = 16 = 128

1 = 2 = 8 = 64 1 = 2 = 16

1 = 8

Ton pound ounces 1 = 2000 = 32000

1 = 16

System of Measurement

• Metric System – used for scientific work in the United States– Measurements are based on the meter– 1 Meter = 100 centimeters (cm)– 1 Meter = 1,000 millimeters (mm)– 1000 Meters = a Kilometer (km)

• Units are in multiples of 10

There are 2 basic rules to use when converting in the customary system.

When going from a known smaller unit to an unknown larger unit, divide.

320 oz = poundsIn this example we know the oz is the smaller unit. We divide 320 by 16 (the number of oz in 1 pound)

known unknown

320 / 16 = 20 pounds

When going from a known larger unit to an unknown smaller unit, multiply.

In this example we know the number of cups is the larger unit. We multiply 12 (the number of fl oz in 1 cup) by 3 cups

3 c = fl ozknown unknown

3 x 12 = 36 fl oz

Inch as a Unit of Measurement

• Traditional unit for woodworking and metalworking

• Some fine rulers or scales have 32 marks per inch.

• Most rulers have 16 marks per inch with each mark equaling 1/16 of an inch.

How To Read a Ruler

• Identify how many marks there are to an inch.

• Measure item and count how many marks past a whole number.

• Reduce to least common denominator

Reading a Ruler

• How many marks are there to an inch on this ruler?– 16

Reading a Ruler

• Locate the marks for 1”, 2”, 3” and 4”• Inch marks are the longest, usually the number

is located under or to one side of the line.

Reading a Ruler

• Look at the lengths of the lines to determine measurement.– The longest line is for a whole number 1

– Next longest line is for 1 /2

– Next longest line is for 1 / 4 and 3 / 4

– Next longest line is for 1 / 8, 3 / 8, 5 / 8 and 7 / 8

– Remaining lines are 1/16, 3/16, 5/16, 7/16, 9/19, 11/16, 13/16, 15/16

Reading A Ruler

• The Letter A represents what measurement?1 inch

ONLINE PRACTICE

• http://www.rickyspears.com/rulergame/

• http://www.funbrain.com/measure/index.html