Chapter 10 – Measurements
and Units
10.1 – U.S. Customary Units
What Measurement and Units Are and
Why They Are Important
When taking measurement, we express quantities in
standardized units such as pounds and yards, which
enable us to compare characteristics of physical
objects.
U.S. Customary Units of Length,
Weight, Capacity and Time
Length
Weight
Capacity
Time
Conversion Examples
1. 6 qt = ____ pt
2. Express 45 min in hours.
3. How many cups are equivalent to 4 gal?
Adding and Subtracting Mixed Units
Some measurements involve more than a single
unit. When a measurement is expressed in mixed
units, we write the larger unit with the largest
possible whole number.
For example, 3 hr 5 min should not be written as 2
hr 65 min
Only quantities with the same units can be added
or subtracted.
Conversion Examples
1.
2.
3.
4.
5.
6.
Convert 3 lb 8 oz to ounces.
Change 328 min to hour and minutes.
Find the sum of 8 ft 4 in and 4 ft 10 in.
Subtract 4 yds 2 feet from 7 yds 1 foot.
Add 3 yds 2 in to 2 feet 3 inches.
The length of a sidewalk is 12 ft 2 inches. The
width of the sidewalk is 3 ft 4 inches. What is
the difference between the length and width?
10.2 – Metric Units and
Metric/U.S. Customary Unit
Conversion
The Metric System
Developed about 200 years ago by a French
scientist, but is now the standard in most countries
for medicine, science, and many other fields.
Length/Distance: Meter
Weight/Mass: Gram
Capacity/Volume: Liter
The Metric System
Other units are formed by multiplying or dividing the base
units by 10.
Base Units
Length/Distance: Meter
Weight/Mass: Gram
Capacity/Volume: Liter
Length: Meter
The millimeter is about the thickness of a dime.
The centimeter is approximately
the width of your little
finger.
The meter is a little
longer than a yard.
Weight: Gram
The milligram is the smallest unit, about the weight of a hair.
The gram is approximately the weight of a raisin.
The kilogram is a about 2 pounds or the weight of the
textbook.
Capacity: Liter
The milliliter is the smallest unit, about as much as an
eyedropper contains.
The liter is slightly more than a quart.
Conversions
You can use the same process we used for
converting U.S. units or use the following
conversions.
Examples
1.
2.
3.
4.
5.
6.
2.4 g = ____ mg
700 m = ____ km
7 L = ____ ml
Express 5 km in millimeters.
Which is the most appropriate for the length
of a pencil? (a) 20 mm, (b) 20 cm, (c) 20 m.
Vitamin C commonly comes in pills with a
strength of 500 mg. How many of the pills
will an adult need to take if she wants a
dosage of half a gram?
Metric/U.S. Customary Unit Conversions
Examples
1.
2.
3.
4.
Express 4 oz in grams.
Express 12 cm in inches
6 qt = ____ L
A prehistoric bird had a wingspan of 8 m.
Express this wingspan in feet.
10.2b – Basic Geometry Conversions
-
Length is an expression of a distance
along a line, such as the perimeter around
your house.
2 ft
3 ft
-
3 ft
3 ft
1 ft
What is the perimeter of these figures?
10.2b – Basic Geometry Conversions
-
Area is the number of square units a twodimensional figure contains, such as the floor of
your house.
-
Determine the area of the figures below and then
convert them to in2. One ft2 = 144 in2. Why is
this?
A  lw
2 ft
4 ft
A
3 ft
1
bh
2
5 ft
10.2b – Basic Geometry Conversions
-
Volume is the number of cubic units required to fill a
three-dimensional figure, such as the amount of space
inside your refrigerator.
-
Determine the volume of the figure below and convert it
to in3. One ft3 = 1728 in3. Why is this?
r = 2 ft
5 ft
V  lwh
2 ft
3 ft
V   r 2h
h = 4 ft
r is the radius of the
circular top.