Grade 9

## Grade 9 Curriculum Outline

#### Projected for Summer 2021

### Missteaks

They are called missteaks because they’re not supposed to work, but they are delicious and full of protein.

We start with the equation

––simply cancel the 6’s. The problem is to find all other examples where the same trickery works.

Another example is

Again find the full set of similar examples. Want more?—how about

But the piece de resistance is yet to come. It starts with

––an apparently inconsequential oddity. But couple that with:

And we have the beginnings of a treasure hunt. Put the class in groups and see who is the first to find the next example.

Teacher manual

### Advertising

__Ticket revenue R and advertising cost C plotted against investment in advertising.__

Use graphical reasoning to decide how much advertising we should purchase to maximize our profit
defined as the difference between our revenue and our cost.

Teacher manual
### Lineup

__Arrivals A and departures D at the ticket window against time.__

That is person # 300 arrives at 8:20 am and is served and departs at 9:00 am. Use graphical reasoning to
answer a number of questions. For example, when is the lineup the longest, and who stands longest in
line?

Teacher manual
### Raptor egg

We have an raptor egg at 10 degrees which needs to be heated to 90 degrees. There are two acceptable methods–– one is to immerse the egg in boiling water and the other is to microwave it at low power. By coincidence, it turns out that the cooking time is the same for both methods––exactly 10 minutes. The graph at the right provides the temperature -time trajectories for each method.

Suppose we can also use a combination of the two––one method for a time followed by the otherand then the other––an instantaneous switch with no temperature loss. a single switch. Can I lower mycooking time by switching?

Teacher manual