ARITHMETIC 303 



from the baseboard to a short distance (say 6 in.) above 

 the lower edge of the border. There is always con- 

 siderable waste in cutting, owing to the matching of 

 the figures forming the design, and the fact that there 

 is a part of a strip left over after cutting up the roll. 

 The parts of strips thus left over are used for the 

 surface above doors and below windows, and other 

 irregular places. Although double rolls are usually 

 counted as 2 single rolls, there is a choice between them 

 in certain cases. Thus, suppose the strips were required 

 to be 9 ft. (3 yd.) long, only 2 strips could be cut from 

 a single roll, or 4 strips from. 2 single rolls, while 5 

 strips could be cut from a double roll. The length of a 

 Toll of border is the same as the length of a roll of 

 paper. 



On account of the waste in cutting, the various sizes 

 and shapes of rooms, the number of windows, doors, etc., 

 it is difficult to estimate exactly the number of rolls 

 required. Two rule's are given, both of which are used 

 in practice: 



Rule. I. From the perimeter of the room, subtract the widths 

 cf openings (windows and doors), and reduce the result to half 

 yards; the number of half yards so obtained will be the total 

 number of strips required. Find the number of strips that can 

 be cut from a roll, and divide the first result by the second; the 

 quotient will be the number of rolls required. 



II. Divide the number of half yards of the perimeter of the 

 room by the number of strips that can be cut from a roll; the 

 quotient will be the number of rolls required. 



If computed by the first rule, the number of rolls 

 obtained may be too small, and if computed by the 

 second rule, too large. But, since paper dealers will 

 usually take back all rolls that are intact, the second 

 rule will generally give the best results, as it will 

 prevent the loss of time required to send to the dealer 

 for extra rolls, in case they are needed. 



EXAMPLE. Find how much paper will be needed to 

 cover the walls and ceiling of a room 15 ft. x 20 ft., the 

 border for both walls and ceiling to be 18 in. wide. The 



