In this lesson, you used two methods to represent and solve problems involving percents: a pictorial model, or percent bar, and the percent proportion.

the percent proportion, percent to 100 equals part to whole

A percent bar allows you to estimate the solution to a percent problem, and the percent proportion allows you to calculate a more exact solution.

Interactive exercise. Assistance may be required. Use the interactive below to summarize how you can use proportional reasoning to determine the whole when you know the part and the percent.

As with any proportional relationship, you can also write an equation in the form of y = kx to describe the relationship, where k is a constant of proportionality.

Video segment. Assistance may be required. View the video below to see how you can write the percent proportion in an equation of y = kx form to relate the part x to the whole y.