MATHEMATICS We have added the following section to supplement the
tables/charts in this appendix. It also provides a refresher for the worker who has
encountered a time lapse between his or her schooling in mathematics and the use
of this subject in the field.
1. To convert square inches to square feet, divide square inches by 144.
2. To convert square feet to square inches, multiply by 144.
3. To convert square feet to square yards, divide by 9.
4. To convert square yards to square feet, multiply by 9.
5. To convert square feet to squares, divide by 100.
Convert 1,550 square inches into square feet.
Convert 15 square feet to square inches.
15 sq ft x 144 sq in. = 2160 sq in.
Convert 100 square feet to square yards.
Convert 10.3 square yards to square feet.
10.3 square yards x 9 square feet = 92.7 square feet
The mathematics problems described in this section are examples only and are
not converted into the metric system. However, if you so desire, you can convert
all of the problems by using the metric conversion tables in appendix I-8 of this
manual. If you need more information on metrics, order The Metric System,
NAVEDTRA 475-01-00-79, through your Educational Services Officer (ESO).
Measurements are most often made in feet (ft) and inches (in.); therefore, it is
necessary that a sheet metalworker know how to make computations involving feet
and inches. In addition, you become familiar with the symbols and abbreviations
used to designate feet and inches, such as the following:
12 inches = 1 foot; 12in. = 1 ft; 12" = 1'
CHANGING INCHES TO FEET AND INCHES
To change inches to feet and inches, divide inches by 12. The quotient will be
the number of feet, and the remainder will be inches.