Carpentry & Building Construction © 2004

Math Activities :

Self-Check Math Activity 9

Decimal Feet

Carpenters sometimes use measurements in the form of decimal feet. Decimal feet consist of a whole number and a part of one foot expressed as a decimal rather than as a regular inch or fraction of an inch. Carpenters may use calculators or tables to convert between decimal and fractional feet.

Terms, Symbols, & Abbreviations
decimal foot - one foot plus a part of a foot expressed as a decimal
' = foot or feet
'' = foot or feet

Practice Exercise

Table A (25.0K)

What is 8' 3 5/16'' in decimal feet?
Step 1	Find the decimal equivalent of the part of a foot, 3 5/16'', from Table A, Decimal
	Equivalents.
	3 5/16'' = 0.2760'
Step 2	Add the whole feet and the decimal together.
	8' + 0.2760' = 8.2760'

Convert 5.4583 decimal feet into feet and fractional inches.
Step 1 On Table A, find the fractional inch equivalent of 0.4583.
0.4583 = 5 1/2''
Step 2 Add the whole feet and the inches together.
5' + 5 1/2'' = 5' 5 1/2''

Problem Exercises

Use Table A to solve the following problems.


1.	5.1719' is equivalent to
		A)	5' 1719"
		B)	5' 17"
		C)	5' 2/16"
		D)	5' 2 1/16"


2.	8.5833' is equivalent to
		A)	8' .5833"
		B)	8' .58"
		C)	8' 7"
		D)	8' 7 7/16"


3.	13.1042' is equivalent to
		A)	13' 1 1/4"
		B)	13' 1/4"
		C)	13' 10"
		D)	13' .1042"


4.	The measurement closest to 4' 6 3/8" is
		A)	4.0313'
		B)	4.5313'
		C)	6.5313'
		D)	6.5365'


5.	The measurement closest to 10.7396' is
		A)	8' 7/8"
		B)	80' 7/8"
		C)	10' 7/8"
		D)	10' 8 7/8"