A usable fraction is a fraction you can use to measure with (i.e., 1/2, 1/4, 1/8, 1/16 inch). You measure with fractions of an inch. However, your calculator works in decimals of an inch.

If you want to convert a decimal to a fraction of an inch, first decide what fraction you want to use - the nearest sixteenth of an inch, nearest eighth of an inch, etc. Then, multiply the decimal by the fraction you desire and round off the answer to the nearest whole number. Use the answer as the top of the fraction.

Convert 2.79 inch to the nearest 1/16 inch.

0.79 x 16 = 12.64.

Round off 12.64 to 13.

Answer: 2.79 inch = 2-13/16 inches.

Adapted from Math for the Technician, by Leo Meyer, available from the Indoor Environment Technician's Library series, www.lamabooks.com.

Publication date: 05/16/2005