## Kid-focused #makered Integration

I struggle to find ways to integrate my #makered work with other 7/8 classes. If teachers have a prep period, it’s during our elective block. Also, when push comes to shove, I’m not sure the 3×45 minute #makered experience is **actually** #makered. Not to get all maker-tao on this, but it’s something I worry about.

Instead, this year I’ve taken advantage of the multi-year relationship I have with many of these kids, and have started to lob interesting things at them via email. As the curricular tech guy when they entered middle school, I’m very likely the first person from whom they received an “official school email.” Sometimes I’m sharing choice bits from my #makered links collection. Other times, it’s a particular problem or project that’s active in the space. Here’s one I sent today to a few of the more puzzle-minded 8th graders.

_____

I made a mistake, and I could use your help.

This will sound like a math problem, but it’s not. I mean, it’s a problem, and I think that math’s probably my best hope to solve it in a way that doesn’t involve undoing and redoing hours of tedious work. That’s actualy, physical, with my hands work! Ugh.

But importantly, this isn’t a problem from the back of a book. This is something that emerged from a weird combination of design, technology, and cultural habits. Oh, and mistakes I made. Because I was in a hurry and didn’t check my work as I was going.

There’s pictures to go with this, but they may not show up “in line” in Gmail.

There’s a clock project in Makers. It’s pretty cool. It will show the hours by turning on individual lights at the end of the little arms.

These lights are arranged in a chain, or strip. This is useful for a bunch of reasons, but the most relevant is that you can turn any of them on/off by referring to it’s position in the strip.

There are 12 lights in the strip (because, you know, clock) but they’re numbered from 0 to 11 (because computers).

Here’s my mistake. Because I was looking at the **back** side of the clock while building it, I wired the lights so that the order of the strip went around backwards. Dumb move on my part, compounded by the fact that I didn’t catch it until I had wired a bunch of **other** stuff in place.

So now the numbered lights in the strip are arranged around the clock like this.

This is bad.

The program reads the **hour** part of time as a integer between 0 and 23. That’s 0<=hours<=23 for those keeping score with interval notation

Can we find a clever way to use math, to create a rule, that maps the integers [0,23] to the integers [0,11] so that the proper light is turned on?

Thanks!

-mr carle

Reasonably sure I am not smart enough right now to deal with minutes, but, if I understand you right:

Assume that the %% (modulo) operator exists in whatever language you’re using. E.g., 8 %% 3 = 2 (remainder after division of 8 by 3), 12 %% 11 = 1, etc. Then I think

“wrong light” = (11 – ((actual hour – 1) %% 12))

Does that work? Pretend it’s 7:00 AM (actual hour = 7). Then ((actual hour – 1) %% 12) = 6 %% 12 = 6, and so the “wrong light” = 11 – 6 = 5. Okay. What about 10 AM (actual hour = 10). Then (actual hour – 1) %% 12) = (9 %% 12) = 9, and so “wrong light” = 11 – 9 = 2. Good so far.

What about 5 PM? (actual hour = 17, right?) Then ((actual hour – 1) %% 12) = (16 %% 12) = 4, and so the “wrong light” = 11 – 4 = 7. WHOOPIE!

(Midnight? That’s 0 actual hour, and -1 %% 12 is, I think, 11, so 11 – 11 = 0 CHECK!)

(Noon? That’s 12 actual hour, and 11 %% 12 is 11, so 11 – 11 = 0 CHECK!)

I have no idea whether this is what you need or not :)

That’s exactly what I’m looking for. :) And I do need it, in the sense that I have a badly wired clock sitting on a table in the Makerspace. A little math major pride on the line – I had actually written out a function that handled the time. BUT! It was a fun moment of recognizing a basic number theory problem emerging from a messy pile of “real life.” That’s what I’m trying to share-out to middle school students.

I’m going to keep the clock counting “backwards” for a few more days, in case some of the 8th graders wander in with ideas. :)

You could also use a map functio or create a data structure that maps the hour to the light number and so the program looks up the hour n the data structure — a hash table maybe — and knows what light to light up.

I didn’t think of using map, although if it was Python I would have considered a dict.

Since these are 8th graders who really only have Scratch as a programming background, neither of those will emerge naturally. I’ll be satisfied if their solution is something other than a 23 part if-elif chain.

Got to this a bit late but hour%13+floor(hour/13) would do the trick.