usually numbered 1 through 12; the mea-
surement starts on the left end of the
ruler, which may or may not be marked
with a “0.” The next divisions, from small-
est to largest, are: The distances between
the smallest increments represent a six-
teenth of an inch, the distances between
the next largest increments represent an
eighth of an inch, the next represent a
fourth of an inch; and, finally, a half of an
inch. (For more about measurement, see
“Mathematics throughout History.”)How can a person calculatethe amount of carpetingneeded to redecorate a
room in a house?
Watching remodeling programs on television, visiting someone else’s house, or even
getting cabin fever in the winter often triggers the need to redecorate from floor to
ceiling. But just how much new carpeting does a house need? The main way to discov-
er how to cover up the floors is by using simple geometry, the branch of mathematics
dealing with area, distance, volume, and the properties of shapes and lines. (For more
about geometry, see “Geometry and Trigonometry.”)
For example, if a person needs to buy new carpeting for a bedroom, just use the
formula A L W, or the area equals the length times the width. For a bedroom that
measures 10 feet by 12 feet, the area would equal 120 square feet. Thus, the room
would need 120 square feet of carpeting.
If a living room has a circular alcove, there is another measurement one can use:
A pi (π) r^2 , or the area (A) equals pi times the radius squared. If the room mea-
sures 12 feet in width at the long end of the alcove (or the diameter of the alcove), the
radius of the alcove is 6 feet. Thus, A 3.14159 (6)^2 , or 113 square feet (rounded to
the nearest square foot), would equal the area of an entire circle. Because an alcove is
half of a circle, divide the 113 square feet in half, or about 56.5 square feet. Add this
area to the rest of the room. For instance, if the rest of the room measures 10 by 12
feet, multiply 10 12 120, then add the alcove area of 56.6 to get the needed
amount of carpeting: 176.5 square feet.Are ratioand proportionimportant in cooking?
Yes, ratio and proportion—two major mathematical concepts—are important in cook-
ing (as is addition, subtraction, multiplication, and division). For example, when a
recipe calls for 1 cup of flour and 2 eggs, the relationship between these two quantities
400 is called a ratio. In this case, the relationship of cups of flour to eggs is 1 to 2, or 1/2,
Measuring a room for a circular rug involves some
basic knowledge of mathematics.