This unit builds on students’ understanding of measurement and introduces the concepts of rate and ratio. Students learn how to calculate ratios and rates during a series of lab activities and conclude the unit with a writing prompt.
Aymara, Giselle, and Reggie discuss the merits about a study that found a correlation between students who text frequently and students who make careless errors while taking tests. They begin a discussion about texting speed and hold a texting contest.
Duration: Approximately 50 minutes
Students distinguish ratio from rate with multiple examples. Students explore the relationship between rates and ratio and percentage. The mini-lesson shows the two ways that we can express a ratio as a comparison of amounts or a comparison with a whole. The lesson also introduces the idea of a unit rate, and it ends with students converting two rates to unit rates.
Duration: Approximately 25 minutes
Students determine their rate of speed while walking at a natural pace (not a race). They collect data in a table, conducting multiple trials and controlling the variables, and then calculate an average and share their findings.
Duration: Approximately 40 minutes
Students examine the correlation of heart rate and breathing rate by collecting data under two different conditions: during rest and after exercising. Students record data at a low- and a high-intensity level of jumping rope. Students convert to unit rates. Students plot data on a graph.
Duration: Approximately 60 minutes
Students design an experiment to determine a basketball player's accuracy, and whether she would have a greater success rate shooting more frequently or taking more time to prepare for a shot.
Duration: Approximately 30 minutes
Student View of Visuals and Activities
Some teachers prefer to have students view the slides and other visual assets in this unit directly instead of projecting them in class. Below is a web page to share with students with links to some of same items that are within in the teacher lesson plans, but without the explanatory text for the teacher.
Original SciGen Unit
This unit has been adapted from "7.3 The Power of Per" in the Word Generation program led by Catherine Snow (Harvard University) through a SERP collaboration with the Boston Public Schools and other districts in Massachusetts and Maryland.
PDFs of that earlier unit's teacher and student editions are available at the Science Generation Download Center.