Missing Proportions Worksheets

How to Find Missing Parts of Equivalent Ratios - Ratios are mathematical expressions where two values with the same units are compared. Ratios are a quantitative relationship between two categories. When solving ratios, you will come across the concept of equivalent ratios. Ratios are said to be equivalent when each of them expresses the same relationship. To determine whether two ratios are equivalent, you can use the cross-multiplication method. Cross-multiplication is when you multiply the numerator of one ratio with the denominator of the other ratio and denominator of the first ratio with the numerator of the second ratio. If the result of both products is equal, the ratios are said to be equivalent. We can use the same cross-multiplication method to find the missing parts of an equivalent ratio. Consider the following example;

18/x = 9/10

This is how you find missing parts of equivalent ratios.


How to Cross Multiply to Solve Proportions

Proportions are a quantitative relationship of a category and the total and are denoted by a double colon. When two rations are equated, it what we term as proportions. There are different ways of finding proportions, and one is the method of cross-multiplication. So, what is cross-multiplication? It is the form of multiplication where the numerator of the first ratio is multiplied with the denominator of the second ratio, and numerator of the second ratio is multiplied by the denominator of the first ratio. It is a method which also helps in calculating a single missing term in two equal ratios.

Pizza Practice

You are making pizza. The amounts in the recipe are for 2 people & you need to cook for 5! Divide all the amounts by 2 to give you the quantities for 1 serving. Multiply the amounts by 5. This keeps your proportions equal. More practice for you: Go to a market and compare prices of items in small and large containers. Figure out which is the better deal by using ratios and proportions. Divide the cost of the item by the quantity of the item to find the "price per unit."