1. PRESENTATION 7 Customary Measurement Units

2. CUSTOMARY LINEAR UNITS
Linear Measurement expresses distance between two points or measurement of lengths
1 foot (ft) = 12 inches (in)
1 yard (yd) = 3 feet (ft)
1 yard (yd) = 36 inches (in)
1 rod (rd) = 16.5 feet (ft)
1 rod (rd) = 5.5 yards (yd)
1 mile (mi) = 5,280 feet (ft)
1 mile (mi) = 1,760 yards (yd)
1 mile (mi) = 320 rods (rd)
1 mile (mi) = 8 furlongs

3. CONVERTING UNITS OF MEASURE
Example: Express inches as feet
Method 1
Since 12 inches = 1 foot, divide by 12
76.53 ÷ 12 =
76.53 inches ≈ feet

4. CONVERTING UNITS OF MEASURE
Method 2
Since is to be expressed as feet, multiply by the unity fraction
This permits the inch unit to be canceled and the foot unit to remain

5. CONVERTING UNITS OF MEASURE
Example: Express 2.28 yards as inches
Method 1
Since 36 inches equal 1 yard, multiply 2.28 by 36
2.28 × 36 = 82.08
2.28 yards ≈ 82.1 in

6. CONVERTING UNITS OF MEASURE
Method 2
Multiply 2.28 by the unity fraction
Divide the numerator and denominator by the common factor, 1 yard

7. SURFACE AREA Two-dimensional measure
Computed as product of two linear measures
Expressed in square units
Unity fractions are used for surface area conversions

8. SURFACE AREA Customary Units of Surface Area
1 square foot (sq ft) = 144 square inches (sq in)
1 square yard (sq yd) = 9 square feet (sq ft)
1 square rod (sq rd) = square yards (sq yd)
1 acre (A) = 160 square rods (sq rd)
1 acre (A) = 43,560 square feet (sq ft)
1 square mile (sq mi) = 640 acres (A)

9. SURFACE AREA CONVERSIONS
Example: Express 728 square inches as square feet
Method 1
Since 144 sq in = 1 sq ft, divide 728 by 144
728 ÷ 144 = ≈ 5.06
728 sq in ≈ 5.06 sq ft

10. SURFACE AREA CONVERSIONS
Method 2
Use the unity fraction to solve

11. CUSTOMARY VOLUME UNITS
Three-dimensional
Computed as product of three linear measures
Expressed in cubic units
Equivalent units of volume:
1 cubic foot (cu ft) = 1,728 cubic inches (cu in)
1 cubic yard (cu yd) = 27 cubic feet (cu ft)

12. CUSTOMARY VOLUME UNITS CONVERSION
Example: Castings are to be made from cubic feet of molten metal. If each casting requires 15.8 cubic inches of metal, how many castings can be made?
Since 1,728 cubic inches equal 1 cubic foot, multiply 1,728 by 2.250
1,728 × = 3,888
Divide
3,888 ÷ 15.8 ≈ 246; 246 castings can be made

13. CUSTOMARY UNITS OF CAPACITY
Capacity is a measure of volume
There are three different kinds of measures of capacity:
Liquid measure
Dry measure
Apothecaries fluid measure (for measuring drugs and prescriptions)

14. CUSTOMARY UNITS OF CAPACITY CONVERSION
English/Metric Units of Capacity:
16 ounces (oz) = 1 pint (pt)
2 pints (pt) = 1 quart (qt)
4 quarts (qt) = 1 gallon (gal)
1 gallon (gal) = 231 cubic inches (cu in)
7.5 gallons (gal) = 1 cubic foot (cu ft)
1,000 milliliters (mL) = 1 liter (L)
1 milliliter (mL) = 1 cubic centimeter (cu cm)
1,000 liters (L) = 1 cubic meter (cu m)

15. CUSTOMARY UNITS OF WEIGHT CONVERSION
English/Metric Units of Weight:
16 ounces (oz) = 1 pound (lbs)
2,000 pounds (lbs) = 1 short ton
2,240 pounds (lbs) = 1 long ton
1,000 milligram (mg) = 1 gram (g)
1,000 grams (g) = 1 kilogram (kg)
1,000 kilograms (kg) = 1 metric ton

16. CAPACITY/WEIGHT CONVERSIONS
Example: How many ounces of solution are contained in a container when full?
Since 16 oz = 1 pt and 2 pt = 1 qt, there are 16 × 2 or 32 oz in 1 qt
Multiply

17. COMPOUND UNITS
Products or quotients of two or more basic units such as mi/hr or lb/sq in
Unity fractions used to convert compound units by placing units on opposite sides of fraction so that they cancel out

18. COMPOUND UNITS
Example: Express tons per square foot as pounds per square inch
Multiply by the unity fractions

19. PRACTICE PROBLEMS
How many strips, each having an area of 36 square inches, can be sheared from a sheet of aluminum that measures 6 square feet?

20. PRACTICE PROBLEMS Convert square feet to square inches
Divide to determine the number of strips
864 sq in ÷ 36 sq in = 24
A total of 24 strips can be sheared from the sheet of aluminum