# Units of Conversion: Square (Area) Measure - Example 4 Basic to the understanding of unit conversion is the understanding of 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.

Square Measure Example 4: Convert 500 hectares to square feet.

Solution: Look for a series of links from hectares to square feet.

• From the table you can see that there are links from hectares to acres to square feet.

• According to the table, 1 hectare is equivalent to 247.1 acres.

Therefore, the fraction is equivalent to 1.

• According to the table, 1 acre is equivalent to 43,560 square feet. Therefore, the fraction is equivalent to 1.

• Rewrite 500 hectares as a fraction and multiply the fraction by 1 two times. • Convert the above 1's to equivalent fractions. • Multiply the numerators and multiply the denominators: • Rewrite the fraction so that the units stand alone: • Rearrange the numerator and the denominator: • Rewrite as several fractions where most fractions have an equivalent value of 1: • Simplify: 5,381,838,000 1 1 1 square foot = 5,381,838,000 square feet

As you work more and more of this conversion problems, you can leave out a lot of steps and simply "cross out" similar units. In the original set-up , you would simply cross out common units and go straight to the expression = 5,381,838,000 square feet

Just be sure that you remember why you are allowed to do the cancelling.

If you would like to work some problems click on Problems. [Units of Conversion] S.O.S MATHematics home page

Do you need more help? Please post your question on our S.O.S. Mathematics CyberBoard. Author: Nancy Marcus

Sun Aug 10 21:07:12 MDT 1997