Proportional Candy Gate Day 2
Lesson 3 of 9
Objective: SWBAT decide whether two quantities are in a proportional relationship through graphing on a coordinate plane and observing whether the graph is a straight line through the origin.
Bell Ringer: Use the Homework task from Proportional Candy Gate Day One for the bell ringer. As students walk in the room instruct them to take out their homework from last night. Students will use their homework sheet to graph the data from the table. Simply hand each student a coordinate grid. Do not instruct students beforehand on how to graph the data from the table. The question at the start of the bell ringer for the students will be:
“Does the data in the table have a proportional relationship, and how can you use the graph to prove or disprove?”
Allow students to engage in mathematical practice 1 and 2. Students will appreciate investigating this on their own and not be given the correct response. The bell ringer also lends itself to MP 4, 5, and 6.
This will allow you to see if you will need to review graphing ordered pairs on a coordinate grid. Many students may need a refresher. Students often mistake plotting points on the correct x and y axis.
Whole Group Discussion
Whole group discussion:
Once students have been afforded about 5 to 10 minutes to graph points, as well as answer the question, go over their thinking as a whole group discussion. Points of interest to hit with students are, correct graphing of the ordered pairs, how to recognize if a line is linear or non-linear, does the line pass through the origin, and if not, will it pass through the origin, does the table represent a constant change between the x-values, and the y-values, how does this affect the graphing of the ordered pairs. Students should be able to recognize patterns between the x and y values which is a practice of MP 8.
Use the Proportional Candy Lab Sheet given in day one’s lesson for this activity. Hand out two more coordinate grid sheets to each student. Have the students graph each table. Repeat the bell ringer activity, MP 1, 2, 4, 5, 6, and 8 will be practiced in this activity.
Students should be able to recognize ordered pairs from the table, graph ordered pairs that are not whole numbers, identify if the lines created are linear and what does that mean for proportionality, and if not, what does that mean for proportionality. Students should compare each graph and use the tables to answer whether the tables and graphs are proportional.
What are the quantities being used?