ADDITION OF FEET AND INCHES
A sheet metal worker often finds it necessary to
combine or subtract certain dimensions which are given
in feet and inches.
Arrange in columns of feet and inches and add
separately. If the answer in the inches column is more
than 12, change to feet and inches and combine feet.
In the changing inches column, we have
SUBTRACTION OF FEET AND INCHES
Arrange in columns with the number to be sub-
tracted below the other number. If the inches in the lower
number is greater, borrow 1 foot (12 in.) from the feet
column in the upper number.
Subtract as in any other problem.
MULTIPLICATION OF FEET AND INCHES
A sheet metal worker maybe required to determine
the total length of metal required to make eight pieces
of duct 1 8 long. To do this, you should be able to
multiply feet and inches by the number of pieces.
Arrange in columns. Multiply each column by the
required number. If the inches column is greater than 12,
change to feet and inches then add to the number of feet.
NOTE: On occasion it might be necessary to mul-
tiply feet and inches by feet and inches. To do this, either
change to inches or change to feet using decimals.
DIVISION OF FEET AND INCHES
Two problems may require the sheet metal worker
to know how to divide feet and inches. An example of
one problem is the division of a piece of metal into an
equal number of parts. The other problem is to deter-
mine the number of pieces of a certain size which can
be made from a piece of metal of a given length.
In dividing feet and inches by a given number, the
problem should be reduced to inches unless the number
of feet will divide by the number evenly.