This Week’s Installment

Poll

What mathematical skill is the textbook trying to teach with this image?

[poll id=”6″]

(If you’re reading via email or RSS, you’ll need to click through to vote. Also, you’ll need to check that link tomorrow for the answer.)

Current Scoreboard

Team Me: 4
Team Commenters: 0

Pseudocontext Submissions

Michelle Pavlovsky

This is may be the worst math problem I’ve seen in my life.

Rules

Every Saturday, I post an image from a math textbook. It’s an image that implicitly or explicitly claims that “this is how we use math in the world!”

I post the image without its mathematical connection and offer three possibilities for that connection. One of them is the textbook’s. Two of them are decoys. You guess which connection is real.

After 24 hours, I update the post with the answer. If a plurality of the commenters picks the textbook’s connection, one point goes to Team Commenters. If a plurality picks one of my decoys, one point goes to Team Me. If you submit a mathematical question in the comments about the image that isn’t pseudocontext, collect a personal point.

(See the rationale for this exercise.)

Answer

Well well well … score one for Team Commenters.

The judges rule that this problem satisfies the first criterion for pseudocontext:

Given a context, the assigned question isn’t a question most human beings would ask about it.

Were you sleep-running the entire time? Why can’t you remember where you ran to and from?

This is Pseudocontext Saturday, so rather than overstep my jurisdiction I’ll let someone else critique the scaffolds in problem #32.

Featured Comment

Hallie:

Dan went for a run. Every 13th stride he sneezes. Every 17th stride he blinks. Every 5th stride a shiver runs down his spine thinking about his homework he has neglected to do. When will he shiver, blink and sneeze at the same time? (Ignore that it is impossible to sneeze with your eyes open.)

This Week’s Installment

Poll

What mathematical skill is the textbook trying to teach with this image?

[poll id=”5″]

(If you’re reading via email or RSS, you’ll need to click through to vote. Also, you’ll need to check that link tomorrow for the answer.)

Current Scoreboard

Team Me: 3
Team Commenters: 0

Pseudocontext Submissions

Michelle Pavlovsky

Paul Hartzer

Rules

Every Saturday, I post an image from a math textbook. It’s an image that implicitly or explicitly claims that “this is how we use math in the world!”

I post the image without its mathematical connection and offer three possibilities for that connection. One of them is the textbook’s. Two of them are decoys. You guess which connection is real.

After 24 hours, I update the post with the answer. If a plurality of the commenters picks the textbook’s connection, one point goes to Team Commenters. If a plurality picks one of my decoys, one point goes to Team Me. If you submit a mathematical question in the comments about the image that isn’t pseudocontext, collect a personal point.

(See the rationale for this exercise.)

Answer

The judges rule that this problem satisfies both criteria for pseudocontext:

Given a context, the assigned question isn’t a question most human beings would ask about it.

I invite any commenter to rationalize the constraint that exactly 15 photos must be purchased and we don’t know which of them will be small or large. More often (always?) people begin with the photos they want, or perhaps they work from a total budget. “I can only buy 15 photos and the number of large photos I purchase can vary from zero to fifteen,” said no one ever.

Given that question, the assigned method isn’t a method most human beings would use to find it.

If most human beings were going to find out the cost of five large photos and ten small photos, they’d multiply each kind of photo by its price. Variables aren’t a useful tool.

So the textbook has made the world serve the math when math should serve the world. If the world doesn’t need math’s service, then math should be gracious enough to step out of the way.

Featured Comments

Jonathan Claydon:

I guessed correctly. The first and third choices made too much sense. Always step up to the plate thinking curveball.

Rachel:

The problem here is that the customer has no use for a general equation, but the store owner might—she’s got to deal with people who call in with all kinds of crazy orders and questions. Still, it’s unlikely the store owner would write an equation for just small and large pictures. It’s much more likely that she’d come up with a pricing scenario for unusual picture sizes.

Current Scoreboard

Team Me: 2
Team Commenters: 0

Come on, team. This is your week.

This Week’s Installment

Poll

What mathematical skill is the textbook trying to teach with this image?

[poll id=”4″]

(If you’re reading via email or RSS, you’ll need to click through to vote.)

Rules

Every Saturday, I post an image from a math textbook. It’s an image that implicitly or explicitly claims that “this is how we use math in the world!”

I post the image without its mathematical connection and offer four possibilities for that connection. One of them is the textbook’s. Three of them are decoys. You guess which connection is real.

After 24 hours, I update the post with the answer. If a plurality of the commenters picks the textbook’s connection, one point goes to Team Commenters. If a plurality picks one of my decoys, one point goes to Team Me. If you submit a mathematical question in the comments about the image that isn’t pseudocontext, collect a personal point.

(See the rationale for this exercise.)

Pseudocontext Submissions

Cathy Yenca

Dear Textbook… why not just measure Becky? #SillyMath pic.twitter.com/B4VuV5FFSK

— Cathy Yenca  (@mathycathy) October 28, 2016

David Petro

Answer

The judges rule that this problem satisfies the first indicator of pseudocontext:

Given a context, the assigned question isn’t a question most human beings would ask about it.

The judges wager that if you lined up 100 arbitrary human-types and asked them the first question they wonder about this context, no more than two of them would ask about how long the ping pong ball is in air.

The judges get the sense that the author of the problem just needed some projectile — any projectile — for the task of calculating total time in air. The tennis ping pong ball [Thanks, Paul Hartzer. -dm], the number drawn on the ping pong ball, and the prize you win for catching the ping pong ball — those are all unrelated to the mathematical work. That’s pseudocontext.