Wood Technology & Processes

Fractions

Fractions express parts of a whole number. A fraction is made up of a numerator and a denominator. The numerator is the number above the line and tells how many parts. The denominator is below the line and tells how many parts are in the whole.

Three types of fractions are proper fractions, improper fractions, and mixed numbers. In a proper fraction, such as 3/4, the numerator is smaller that the denominator. In an improper fraction, such as 2/2 or 7/2, the numerator is the same or larger than the denominator. A mixed number has a whole number and any type of fraction. An example is 3 1/2.

Woodworkers measure and lay out materials using all of these fractions. Improper fractions are usually converted to proper fractions or mixed numbers. Woodworkers use fractions when measuring the thickness of materials and the depth of mortises.

Practice Exercise

Convert the improper fraction to a mixed number.

1.		The improper fraction 9/2 is the same as
			A)	2/9
			B)	4
			C)	4 1/2
			D)	9 1/2
2.		11/4 is the same as
			A)	11 1/4
			B)	2 3/4
			C)	2/4
			D)	2
3.		30/8 is the same as
			A)	3
			B)	2 3/4
			C)	3 1/4
			D)	3 3/4

Practice Exercise

Convert the mixed number 3 1/2 to an improper fraction.

4.		The mixed number 2 3/4 is the same as
			A)	6/4
			B)	11/4
			C)	8/3
			D)	11/3
5.		The mixed number 5 3/8 is the same as
			A)	43/8
			B)	53/8
			C)	40/8
			D)	15/8