Big Ideas:

If units are related, you can use that relationship to predict “how many” of one unit, if you know “how many” of the other.

If you use a bigger unit, you need fewer of them

Proportional reasoning is about unitizing, grouping it, counting the groups and thinking of comparisons multiplicatively.

Expectations:

• B2.9 represent and create equivalent ratios and rates, using a variety of tools and models, in various contexts

Show students the act 1 video.

Then ask students to do a rapid write of what they notice and what they wonder.

Students will then share out their noticings and wonderings while I jot their ideas down on the whiteboard.

While some great wonderings may arise, the first question we will address is:

How many sticky notes will it take to hold his weight?

Some of the best mathematical discourse can be had when asking students to make predictions without having enough information to know for certain. Extraneous factors such as how heavy you believe the person is, what brand of sticky notes we will use and how big each sticky note is can have students debating back and fourth over whose prediction seems most reasonable.

Once students have been given some time to think independently, discuss with neighbours and as a whole group, jot down some predictions.

• Show students the act 3 video to see whether 10 slings will hold his weight.

How many sticky notes (or slings) will it take to hold your own weight?

This question might be too personal for students, especially for those sensitive to their weight. You might want to consider giving them set weights of items such as:

• Your own weight (if you’re comfortable with that)

• Weight of a dog

• etc.

If you (the teacher) is willing to participate in an experiment, you could have the class calculate how many sticky notes they believe you’ll need to hold your weight and then actually test it out!

SEL Self-Assessments (English) and Teacher Rubric