Shopping is a universal interest with students. They've learned about money and how to acquire things they want by observing their parents. By fifth grade, they've earned some of their own money through chores or an allowance. Showing them how to compare prices and quantities can teach them about percentages. Is an 8-ounce soft drink for 69 cents a better value than a 12-ounce drink for 85 cents? Students can calculate the cost of each drink per ounce and per dollar to determine which is a better value. If one cereal has 8 grams of fat in 14 ounces and another has 7 grams in 12 ounces, which has more fat and how much more?
Kids love sports cards. Indirectly, they learn about percentages every time they read a batting average or fielding average. For instance, a hitter with a .310 batting average got a hit in 31 percent of his official at-bats. Have kids calculate the batting average of hypothetical players who, for example, got 103 hits in 309 official at-bats. The same can be done for other statistics, including fielding average and, with a few more calculations, earned run average. For advanced students, there are more complicated metrics that measure, for example, the percentage of times a batted ball is a single or double.
Students can compute several different percentages from the dining experience. For example, if a restaurant is offering 30 percent off dinner before 6 p.m., and a hamburger platter regularly costs $9, how much will the student save? Have students calculate the cost of different dinners after adding 10-percent tax and a 15-percent tip, or the cost of dinner for two if one is full price and the second half-off.
Appeal to students' interests by conducting polls in class. Students can be asked to vote for their favorite TV show or Disney movie, predictions about college tournament champions, or winners of Emmy or Academy awards. Compile the answers into a chart and have the students convert the raw numbers to percentages. Vary the number of choices in each poll to make the conversion more challenging.