Proportions
This past week my class covered a until lesson on proportions. I wanted a bit of refresher on the subject so I went to the Math Antics channel on YouTube. Lately, I've been using Math Antics quite frequently. It has been a useful instructional tool, helping me to brush up on my mathematical knowledge and skills. The strength of Math Antics as a learning tool is the way they present each problem. The math lessons they provide are very clear, slowly delivered, and gradually progress in difficulty. For example, in the video on proportions above the instructor first provides a reminder of what fractions and ratios are before moving on to define proportions. His first lesson on proportions explains the technique of cross multiplying to find an unknown value. This lesson attempts to be as simple as possible, allowing students to gain a basic grasp of how to find unknown values in proportional problems. Following this, the second lesson is a little more difficult. Applying proportions in a practical way, the instructor uses the example of a map of Hawaii to show it's proportional relation with the actual island of Hawaii. This lesson proceeds to explain how to find an unknown value by using division. Overall, what is presented is a clear and concise lesson on how to understand proportions and how to calculate unknown values in proportional problems.
Learning proportions is a requirement for grade eight in the The Ontario Curriculum, Grades: 1-8 Mathematics. A specific requirement of the curriculum states that students should be able to "solve problems involving proportions, using concrete materials, drawings, and variables" (Ontario Curriculum, 112). In the Math Antics video supplied above the instructor provides a good example of this specific curriculum requirement when he employees the use of a map. Using the map to calculate proportions is a good practical lesson that can be used with students.
For example, a fun exercise might require students to break up in to small groups. Each group is given a map with a list of cities on it. Group members are to imagine they are a flight crew travelling to each of these cities listed in the specific order or "flight plan." Using what they know about proportions each group must calculate the total number of kilometers traveled by their flight crew over the course of their entire journey. Each group could have different flight plans or even maps of different proportional sizes. The group that calculates the correct total amount of kilometers they have traveled wins a prize. If there is time left after this activity student could be asked to estimate how far away they think a particular city is (e.g. how far do you think Hamilton, Ontario is from Vancouver, British Columbia? Etc.). Students can then measure and use their working knowledge of proportions to find out which estimation is the closest. First to find the calculation correctly and closest estimation gets a prize.
In closing, I will add a few final thoughts about Math Antics and it's potential instructional value. In particular, one possible use for instructional videos like Math Antics is it's potential to be used in the flipped classroom model. Students can view this video prior to class, devoting more in-class time to questions and, for instance, the flight plan activity example I have provided. By employing the flipped classroom model and using sources with quality videos like Math Antics, instructors can devote more their time to organizing meaningful activities and helping students that are struggling with comprehension.