# Units of Conversion: Linear Measure

Basic to the understanding of unit conversion is the understanding equivalence, the understanding of the multiplicative identity of 1, and how the two are related. For a review of these concepts, click on Review.

If you have forgotten how to manipulate fractions, visit Fractions for Adults on SOSMath for an in-depth review.

Review the following table (Webster's New World Dictionary, Second Edition, Simon and Schuster, 1982) of Standard Units of Conversion to see if you can create fractions that have a value of 1. You can click to examples following each table.

LinearMeasure

Example 3: You are traveling in Mexico and the speed limit is 80 kilometers per hour. Your car speedometer reads in miles. What is the speed limit in miles?

Solution:

• The speed limit of 80 kilometers per hour can be written as the fraction

.

• Multiply by 1 in the form :

• Multiply the two fractions:

=

• Rearrange the numerator so that the word kilometer is to the right.

• At this point, you could simply cancel the kilometer in the numerator with the kilometer in the denominator. Be sure that you understand why you can do the canceling.

• If the speed limit is 80 kilometers per hour, you would be safe if you kept your car just under 50 miles per hour.

If you would like to review another example, click on Example.

If you would like to practice some problems click on Problems.

[Units of Conversion]