A proportion is a statement that two ratios or fractions are equal. In other words, it shows the equality of two ratios. It can be represented in the form of a/b = c/d, where a, b, c, and d are numbers and b and d are not equal to zero.
Example:
If we have the proportion 2/3 = 4/6, it means that the two fractions are equal to each other, because when we simplify 4/6 to 2/3, the result is the same as the first fraction.
Study Guide:
Understanding Ratios: Before studying proportions, it's important to have a good understanding of ratios. A ratio is a comparison of two quantities. For example, if there are 3 red balls and 5 blue balls, the ratio of red balls to blue balls is 3:5.
Writing Proportions: To write a proportion, you need to set up two equal ratios. For example, if the ratio of boys to girls in a class is 3:2, and the total number of students is 25, you can write the proportion as 3/2 = x/25, where x represents the unknown number of girls in the class.
Solving Proportions: To solve a proportion, you can use cross multiplication. For the proportion a/b = c/d, the cross products are ad and bc. You can set up the equation ad = bc and solve for the unknown variable.
Applications of Proportions: Proportions are used in various real-life scenarios, such as solving problems related to cooking recipes, map scales, and financial calculations.
Understanding proportions is important in various mathematical concepts, and it forms the basis of solving many problems in mathematics and real-world scenarios. It's a fundamental concept that is used in everyday life.
Specify locations and describe spatial relationships using coordinate geometry and other representational systems.
Make and use coordinate systems to specify locations and to describe paths.
Connections to the Grade 5 Focal Points (NCTM)
Data Analysis: Students apply their understanding of whole numbers, fractions, and decimals as they construct and analyze double-bar and line graphs and use ordered pairs on coordinate grids.