### Buy my book!

### Volunteer at the Minnesota State Fair!

Math On-A-Stick is coming to the Minnesota State Fair August 27â€”September 7. We need volunteers for 3 hour shifts. Click here to sign up.

Find more information on our Math On-A-Stick page.-
### Recent Posts

### Comments

- Max Ray (@maxmathforum) on Summertime (or anytime) reading recommendations
- Christopher on Fruit snacks
- Monica Cataldo on Fruit snacks
- Christopher on Fruit snacks
- Chris Lusto on Fruit snacks

### What have people read recently?

### Subscribe by RSS

### Categories

- Assessment (5)
- Connecting teachers (3)
- Courses (8)
- Curriculum (48)
- Diagrams and decorations (12)
- For further learning (1)
- Language (14)
- Launch (3)
- Lessons (20)
- Metaphors (3)
- News (40)
- Opinion (38)
- Presentations (4)
- Problems (math) (46)
- Problems (teaching) (39)
- Questions from middle school students (10)
- Questions from middle school teachers (6)
- Reflection (36)
- Talking math with your kids (75)
- Technology (14)
- The end of word problems (19)
- Truly unfortunate representations of data (8)
- Uncategorized (31)

### Tags

4 years old 5 years old 6 years old 7 years old 8 years old addition algebra algorithms borders calculus ccss CGI CMP college algebra common core counting curriculum data decimals developmental mathematics diagrams division division of fractions fractions functions geometry graphs Griffin groceries hexagons inverse iwb khan khan academy language lattice learning listening to students logarithms math math for elementary teachers math methods measurement middle school multiplication nature of mathematics nctm new york times number number language numeration online learning oreos ph place value probability problems professional development questions rate rates ratio ratios sharing standards systems of equations Tabitha TDI Technology twitter units video wcydwt wiggins word problems### Stuff I write

### Support the work

AWESOME. ^_^

What he said. I’m not sure how evocative it is as a standalone image, but it’s quite clever with just a bit of thought.

Have you ever used this with your students? If so, how did they react?

The vending machine metaphor actually resonates with my College Algebra students pretty well every semester. Several students have come back to me and mentioned using vending machines to think about functions in later courses.

Of course, we deal with the formal definition of function, and with more abstract imagery as well. But I really do think we ignore this sort of informal imagery at our (and our students’) peril. They’ll form images whether we support that process or not.

And I’m agreed that these don’t work as standalone images. You do need to think them through, and discuss them.

Plus they’re fun.

Oh, by the way. I don’t

testmy students on their ability to use the vending machine metaphor. The standard is about functions. Vending machines are a route to the standard, but are not the standard.Pingback: Actually, it’s not like that at all… (failed metaphor) | Overthinking my teaching

Christopher, how do you expand on this with the students?

What’s the domain and range of your “identity” function?

Values. Domain is {1,5}. Range is {1,5}. Function is {(1,1), (5,5)}.

Pingback: Sameness in College Algebra | Overthinking my teaching

I love this. I normally usee the example of a toaster. The white bread is the input; the toaster is the FUNction rule; the toast the output. NOW, what type of FUNction is the toast? If I put in rye bread, I still get toast out, just like if I toasted wheat.

Thanks for the ideas and for keeping me thinking how I approach the topic of FUNctions w/ my students.

I love the different vending machines idea.

Oh, one thing I try to do is ask my students what do they see…in hopes of getting to ‘sameness’. Maybe there’s something they see I don’t see.