ADDITION OF FEET AND INCHESA sheet metal worker often finds it necessary tocombine or subtract certain dimensions which are givenin feet and inches.Arrange in columns of feet and inches and addseparately. If the answer in the inches column is morethan 12, change to feet and inches and combine feet.Example:In the changing inches column, we haveSUBTRACTION OF FEET AND INCHESArrange in columns with the number to be sub-tracted below the other number. If the inches in the lowernumber is greater, borrow 1 foot (12 in.) from the feetcolumn in the upper number.Subtract as in any other problem.Example:MULTIPLICATION OF FEET AND INCHESA sheet metal worker maybe required to determinethe total length of metal required to make eight piecesof duct 1’ 8“ long. To do this, you should be able tomultiply feet and inches by the number of pieces.Arrange in columns. Multiply each column by therequired number. If the inches column is greater than 12,change to feet and inches then add to the number of feet.Example:NOTE: On occasion it might be necessary to mul-tiply feet and inches by feet and inches. To do this, eitherchange to inches or change to feet using decimals.DIVISION OF FEET AND INCHESTwo problems may require the sheet metal workerto know how to divide feet and inches. An example ofone problem is the division of a piece of metal into anequal number of parts. The other problem is to deter-mine the number of pieces of a certain size which canbe made from a piece of metal of a given length.In dividing feet and inches by a given number, theproblem should be reduced to inches unless the numberof feet will divide by the number evenly.Example:Example:AII-2