Fun with Functions

httpv://www.youtube.com/watch?v=OlO8RvA3Jb4

If you’ve been burned on school math, like I have, you might cringe at the idea of introducing functions to your child. Children don’t start studying functions until later in school. But why wait? After all, children learn about functions very early on through toys as well as daily observations. Besides, functions can be way cool or at least familiar to all involved.

Think about your dishwasher – you put dirty dishes in (input) and, after a while, take the clean dishes out (output). As long as the input is consistent and your dishwasher doesn’t break, the output will be the same – clean and dry dishes. That’s an example of a function machine that even the youngest children are familiar with and curious about.

A vacuum cleaner is another example of a function machine. If you happen to have a model that allows certain adjustments, you can make your vacuum blow air out instead of sucking it in. In which case it is a machine with an inverse function.

So there you go, these are

BIG Math Concepts

  • Function
  • Input
  • Output
  • Inverse function
  • Transformation
  • Result

Take a look at your child’s toys. How many of these are function machines? In my house we have a couple of marble runs, several remote-controlled cars, a no-longer-used shape sorter that makes a sound with every correct match, and many others. All these toys are function machines. I bet you have quite a few of these on the shelves and in the toy boxes.

You can also invent a machine all of your own. Sketch or build a “function machine” that takes objects in and then transforms them. Make up a rule your child will be able to guess, but not immediately. Let the child put in objects or numbers a few times to see what happens to them and to guess the transformation rule. Take turns building more machines and guessing their rules!

Experiment with functions that find correspondences:

  • input: age, output: age two years ago
  • input: female animal, output: male animal (mate), for example, hen-rooster, doe-buck
  • input: baby animal, output: adult animal (help babies find parents), for example, kitten-cat, puppy-dog

Infants  – Use qualitative functions, for example, a machine that adds a sticker to each toy the baby throws into it, or a machine that finds its mommy for each baby animal

Toddlers – Invite toddlers to change the first object and then repeat that same operation on other objects, for example, give each toy animal its favorite food (dog-bone, bird-seed, rabbit-carrot). Start using simple quantitative functions, such as the machine doubling whatever enters into it, or giving every character two raisins to eat (so, if several enter, you need to prepare enough raisins).

Older Children – Kids enjoy making up fancy machines that are hard to guess. Once you have the game going, you can play it in the car or on walks, for some oral computations. Kids may argue if the guess, “The machine doubles” is correct about their “Add the number to itself” function – help them figure out what’s going on!

Other ways to explore function machines

  • Story ideas: Many fairy tales and science fiction stories have magical or mechanical objects that transform you or your stuff powerfully, for example, people turning into animals and back, cooking lots of porridge, or building palaces.
  • Find function machines in everyday life. Some turn dirty clothes or dishes into clean ones, others turn cold things into hot things, or paint the object another color.
  • Build the function machine that gives each animal its “house” or habitat; again, you will need pictures. A wonderful book for this activity is Mary Ann Hoberman’s “A House is a House for Me”.
  • Play with the function machine that makes animal sounds for each animal that enters. You can use toys.
  • The mirror machine: when the kid draws anything and inserts it into the machine, it makes the mirror image of it on the same paper.
  • The upside-down machine turns everything that enters upside-down. Make sure to invite the kid to enter!
  • The zero machine: a critter in the machine eats everything that comes in. Out of the machine always comes – nothing!
Hooray, functions can be fun! Have you tried finding, building or exploring function machines with your child?
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Posted in Make

Rube Thursday

Happy Rube Thursday! It is a new thing I would like to start – a day to celebrate Rube Goldberg machines, the over-engineered contraptions that perform a very simple task. Think Mouse Trap game for this one. To kick off what I hope to become an online collection of Rube Goldberg machines, here’s a short video.

http://www.youtube.com/watch?v=0VlEh-CPMss

 

Where Is Math? Tell us what you find! Here is what we see:

  • Algorithms. Each machine works step-by-step, doing different but connected things at each step.
  • Iterations. If at first you don’t succeed, try and try again.
  • Applied math in physics: simple machines. Levers, inclined planes and more!
Send us photos and videos of your kids making Rube Goldberg machines.

 

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Posted in Grow

“The Cult of Right Answers” by David Albert

After we posted “Can you let them fail?” there was a lovely discussion at our Facebook group. As a part of it, David Albert (above) offered the Moebius Noodles community an excerpt from his latest book. David describes himself as father, husband, author, magazine columnist, itinerant storyteller, and speaker. Here is the gem from David:

The Cult of Right Answers

 

Ring the bells that still can ring.
Forget your perfect offering.
There is a crack in everything.
That’s how the light gets in.
– Leonard Cohen,

“Anthem”

I grew up in the cult of right answers. To this day, I’m sure I don’t know quite why my schools thought it all that important to initiate me into the cult. My wife in her antiquarian pursuits balances the family checkbook. She says the bank is virtually always right, so if things are more than a few cents off, she assumes she got something wrong, and adjusts accordingly to make things conform. Meera, my future-accountant daughter, would likely do the same, though she’d bother about the pennies as well.

In my quantitative work in my day job, when my hunch is that things are “off”, I’ve learned over time that it is almost never the result of a math error, but because of a problem at the data entry point, a computer shut-down, or any number of exigencies having virtually nothing to do with arithmetic. I have learned to look for results that are consistent; unless I have alarm bells set off elsewhere, I almost never examine them to see whether they are right.

 

 

When I go to the grocery store to buy a jar of spaghetti sauce ($1.89 on sale) and a package of spaghetti ($.99), if I want to know whether I’ve got enough money, I always add from left to right (just how I was taught not to do when I was in school), I estimate well enough, and I pay absolutely no attention to the fact that the final digit in the addition is “8”. Since I am likely to pay for it with my debit card, I am not going to count the change either.

 

 

I do the same with estimating the time the bread is baking in the oven (have any of you actually checked the accuracy of the electronic timer?), how long it will take to defrost the chicken in the microwave, my gas mileage or the distance to my destination, or the amount of salt to put into the dish when the recipe calls for “a pinch”.

 

 

And so, looking back at my school experiences, it is difficult to see what purpose the cult of right answers, which extended far beyond the world of mathematics, served, other than as an odd kind of social sorting mechanism. The successful competitors (including me) sat on the edges of our seats, ready to perform our next trick and obtain a herring from our trainers, the less successful got hungrier in the back until many forgot what food was. But the actual purpose for my initiation was, I believe to this day, to indicate that they thought they “owned” me, and that, deep down, I was one of them. Am I? In more than 30 years of deschooling, this is something that I am still trying to figure out.

 

 

There is nothing wrong with right answers of course. When I drive over a bridge, I am depending on the architect and builder having calculated the load capacity correctly. I need to be sure that the loan calculator used to figure out my mortgage payment is accurate, and I want to feel certain when I read that someone other than Ichiro has won the American League batting championship.

 

 

That’s all well and good, but I think it can’t be emphasized enough how the cult of right answers can be damaging to one’s capacity to learn, and can stymie both creativity and curiosity. And this is true whether one turns out to be good at it or not.

I was most definitely a science and math nerd in school, and was well-rewarded and advanced in the cult for my right answers. I also had some very concrete experience of what happened when the “right” answer (you’ll see the reason for quotations marks in a minute) wasn’t forthcoming.

 

 

This is a tale not even my mother knows. I was nominated for an all-expense-paid, two-week trip to a newly established (soon to be prestigious) math camp, for which we had to take a competitive exam. There were six scholarships awarded. There were 50 questions, each worth two points. Six of the competitors scored 100 points on the exam. I scored a 99. Why? In a geometric proof, I left out A=A. Well, duh! This is more Gertrude Stein (“A rose is a rose is a rose”) than Isaac Newton. I can’t imagine there is a mathematician in the entire universe who would have cared (though I never really met a mathematician until I was in my mid-20s), but I learned my lesson well.

 

 

I never took a single math course after high school; now I use quantitative analysis in my daily work. Go figure.

I often recommend the wonderful book The Number Devil: A Mathematical Adventure by Hans Magnus Enzensberger to homeschoolers. The book is engaging and very well written, nicely illustrated, and opens up a world of mathematics to children and youth that they might otherwise never know was even there. It was originally written for 10-11 year olds, I think, but I have actually discovered that children as young as seven (some of whom having had it read to them) find great pleasure in it.

 

 

And, yet, I have a confession to make. I recently retrieved my copy down from the shelf and read it for the third time. Each time, I experience the same response, a falling feeling in the pit of my stomach. I want to put it down, but I fight through the queasiness. The number devil poses conundrums that cannot be solved, provides answers that are clearly correct but cannot be explained, and are intended to excite a general sense of wonderment at the wide, beautiful world of mathematics. But the feeling of wonderment when it comes to mathematics was confiscated from me when I joined the cult’s inner circle. And like my permanent record, it seems to have disappeared into the ether long ago, and it is awfully difficult to cultivate it anew.

 

 

The cult of right answers is based at bottom on the fear of wrong answers, fear of failure, fear of error, fear of disappointing those upon whose favor one has come to depend on for one’s self-esteem and self-worth. It may work short-term, but in the longer run, fear is a very poor motivator for learning, and a prime cause of apathy. For while a continuous string of right answers might assuage fear for a while, an equally effective way of coping with fear is to cultivate a feeling that learning really doesn’t matter, or to deliberately (even if sometimes unconsciously) respond with wrong answers so that external expectations are lowered, or to simply attempt to absent oneself from the entire enterprise. After one experiences failure enough times and sees that the short-term consequences are really not so devastating, apathy born of failure becomes an acceptable response. Once having become discouraged, humiliated, baffled, or fearful, an apathetic silence can become a welcome refuge.

This silence can easily be reinforced, of course. Most of the days I passed in school I spent with the ‘know-it-alls’. They expended most of the day talking at me. It might have been the case that they were there to answer our questions, but it quickly became evident, as virtually every school child knows, that the know-it-alls (the teachers, of course) asked 95% of the questions, and 98% of the time already knew the answers. Sometimes there were “discussions”, which never really resembled anything like discussions in the real world; they were just manipulative tools for soliciting right answers. How many times I can remember the leading questions being answered by a classmate in a way already predetermined to being just not quite right, and the teacher calling on someone else to remedy the ‘ignorance’ displayed by the first responder. Shame and learning cannot occupy the same psychological space at the same time, for when they are forced into the same box, the only likely result is loss of self-respect….”

Some of Davids’ books:

 

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Posted in Grow

Can You Let Them Fail?

One of the hardest things for me as a parent is to watch my son fail. I know I am not the only one like that – watching over our kids, protecting, suggesting right solutions, correcting just in time before they fail whether on a playground or in a classroom.

But, as Roger Schank writes in his book Coloring Outside the Lines, “you can’t learn unless you are willing to fail”. Failing compels one to try it again (aka practice) and/or try it again differently (aka creative approach).

Bon at MathFour.com frequently talks about the importance of inquiry-based instructions. She says

One of my favorite to teach… is through letting the students be “King for a Day”. I give them a never before seen math problem and allow them to make the rules on how to solve it. As they make the “wrong” rules, they will play with them and see that they can’t work. That’s the beauty in it! Just make sure to encourage them to do some problems (i.e. experiment) with their new rules so they can make sure it works fine.

So next time I am tempted to rush in and save my son’s block structure from toppling or nudge the right puzzle piece closer to him or inflect my voice just so when asking him which element goes next into a pattern, this one or THIS one, I will count to 10 and repeat the “let him see for himself” mantra. And yes, through my son’s failures I will experience my own ones. But I think the “you can’t grow unless you are willing to fail” rule works for adults as well. I am prepared to test it. Will you join me?

by Yelena

Image source: by Nationaal Archief on Flickr.com

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Posted in Grow