In this section, we will use the fraction notation. When a ratio is written in fraction form, the fraction should be simplified. If it is an improper fraction, we do not change it to a mixed number. Because a ratio compares two quantities, we would leave a ratio as instead of simplifying it to so that we can see the two parts of the ratio.<\/p>\n
We will often work with ratios of decimals<\/a>, especially when we have ratios involving money. In these cases, we can eliminate the decimals by using the Equivalent Fractions Property to convert the ratio to a fraction with whole numbers in the numerator<\/a> and denominator<\/a>.<\/p>\n You do not have to write out every step when you multiply the numerator and denominator by powers of ten. As long as you move both decimal places the same number of places, the ratio will remain the same.<\/p>\n One real-world application of ratios that affects many people involves measuring cholesterol in blood. The ratio of total cholesterol to HDL cholesterol is one way doctors assess a person\u2019s overall health. A ratio of less than to 1 is considered good.<\/p>\n The Canadian National Building Code<\/a> (CNBC) Guidelines for wheel chair ramps require a maximum vertical rise of inch for every foot of horizontal run. What is the ratio of the rise to the run?<\/p>\n Solution<\/strong><\/p>\n In a ratio, the measurements must be in the same units. We can change feet to inches, or inches to feet. It is usually easier to convert to the smaller unit, since this avoids introducing more fractions into the problem.<\/p>\n Write the words that express the ratio.<\/p>\n Sometimes we buy common household items \u2018in bulk\u2019, where several items are packaged together and sold for one price. To compare the prices of different sized packages, we need to find the unit price. To find the unit price<\/a>, divide the total price by the number of items. A unit price is a unit rate for one item.<\/p>\n division to one more place to see the difference between the unit prices.<\/p>\n Have you noticed that the examples in this section used the comparison words ratio of, to, per, in, for, on, and from? When you translate phrases that include these words, you should think either ratio or rate. If the units measure the same quantity (length, time, etc.), you have a ratio. If the units are different, you have a rate. In both cases, you write a fraction.<\/p>\nApplications of Ratios<\/h3>\n
Find Unit Price<\/h3>\n
Translate Phrases to Expressions with Fractions<\/h3>\n