Author: Bon Crowder

  • Math Teachers at Play Blog Carnival #42

    Math Teachers at Play Blog Carnival #42

    To mix things up a little, this month’s Math Teachers at Play Blog Carnival is a love story – between two people and then their new cute daughter. It’s a story of the coolest carnival of all – having kids.

    The Story of Bernice and John, Mathematician Parents

    by Bernice Abel

    When John and I decided to have children, I knew we would be Making More Math Geeks. And I was okay with that. I was actually quite excited about it.

    “How many kids do you want?” he asked before we were married. I thought about it a bit and said, “I probably want an odd number of kids.”

    “What base is that in?” He asked me. I swooned. Could it be that he knew about Odd Numbers in Odd Bases? One thing was for sure, I knew he was Asking Good Questions. Especially when he asked me to marry him!

    “You know,” he said, “We should have just the right number of girls and just the right number of boys. The Golden Ratio of our own, so to speak.”

    There were so many things to be in love with in this man!

    The day daughter was born was a life scalar multiple.

    When I went into labor, I had just finished some Mathematics Crosswords  and started an article called, “Curriculum Choice Review: Key to…Math Curriculum.” We raced to the hospital just in time for our sweet daughter, Clementine, to be born.

    I immediately asked for pizza.

    “Why pizza?” He asked.

    “I don’t know,” I said, “I just gave birth to a math geek, so I’m feeling like I should be eating 1/8, 1/4, or even 1/2 of something. I really don’t want our new daughter needing Fraction Help. And I know this hospital has pizza cut into 8 slices.”

    He said, “You know, The (Mathematical) Trouble with Pizza is…” And then I glared at him. “Get me some pizza!” I screamed. The love of a math guy was wearing off.

    “What took you so long?” I asked when he finally got back with my pizza. “You didn’t have to calculate any tip, and even My New Percent Lessons wouldn’t have helped you figure out the tax – the cash register does it all!”

    “I was Actually Doing Day One Airplanes,” he said.

    “What does that mean?” I replied.

    “You know,” he said, “A little Math and Fun.”

    I said, “My idea of math and fun is some Tesseracts and Factor Lattices. And I didn’t have either to keep me entertained while you were gone.”

    I didn’t mention my desire for a iPad even though I had heard of the new fad of iPad Gaming in Math and Science. Money was tight and Clementine was already proving to be an expensive bundle of cuteness.

    “Don’t even act like you were sitting around bored. You surely were writing some math ed thing like, 5 Tips For Coaxing Dreaded Maths Corrections From Your Child.”

    He knows me so well!

    The Last Few Math Teachers at Play Carnivals
  • Support Our Math Future: Moebius Noodles

    Support Our Math Future: Moebius Noodles

    Moebius Noodles is a program being created for early math learning to support parents and teachers.

    It will be an online book and online community with activities that you can use, copy, change and share.

    The online book will have activities that you can use, copy, change and share.

    The online community will support the users and creators of the book.

    Moebius Noodles will be everything you need to support your early math learners.

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  • The Math in Credit Card Security

    The Math in Credit Card Security

    We had a fun little discussion via email at the day-job. Someone changed the code on the combination lock and the discussion around combinations, permutations, cryptography and all things sneaky-math cranked up.

    It reminded me of this neat fact I learned about credit card security.

    Not all digits on a credit card are created equally!

    A credit card is made up of 16 numbers. But only the first 15 are “random,” according to NRich Math. The last number – the 16th number – is the “check digit.” It’s calculated using a fancy formula using the first 15 digits.

    This check digit helps a computer system quickly determine if a credit card number is fake. Now, it can’t confirm that it’s real – it just can help determine if it is fake.

    The digit is created using a method called Codabar.

    First, let’s define some things.

    An odd digit is a digit in the credit card number that is in an odd position. For the photo of the card here, the number is: 5184 8204 5526 6423:

    The odd digits are 5, 8, 8, 0, 5, 2, 6, 2

    An even digit is a digit in the credit card number that is in an even position. For the photo of the card here, even digits are 1, 4, 2, 4, 5, 6, 4, 3

    The check digit is the last digit – it gets calculated and isn’t considered in either odd or even position. It’s a super special digit.

    The method is weird – and kinda fun!

    Here’s what you do:

    1. Add up all the odd digits, or the digits in the odd positions: 5 + 8 + 8 + 0 + 5 + 2 + 6 + 2 = 36
    2. Double that number: 36 × 2 = 72. Save this number, 72, for later…
    3. Add the even digits together, or the digits in the even positions: 1 + 4 + 2 + 4 + 5 + 6 + 4 + 3 = 29. Save this number, 29, for later…
    4. (This is a freaky step.) Count the number of odd digits that are greater than 4. The odd digits are 5, 8, 8, 0, 5, 2, 6, 2. Of these, 5, 8, 8, 5 and 6 are bigger than 4. There are 5 of those total. Save this number, 5,  for this next step…
    5. Add up the results you saved from steps #2, #3 and #4. 72 + 29 + 5 = 106
    6. Take the answer from step #5 and figure out how many you need to add to get it to the next multiple of 10 (or the next number that ends in zero). The number after 106 that ends in zero is 110. So we need to add 4. 106 + 4 = 110. 4 is the super important number.
    7. That final super important number – well, that’s the check digit! That’s the last number that should be on the credit card – if it were a real card!

    For the picture, the check digit should be a 4. And it’s a 3. So I can tell instantly that this is a fake credit card number.

    You can use this to teach your children!

    Stuck in a waiting room with a 10-year-old? All you need is a pen, piece of paper and any credit card in your wallet.

    Teach them the method and have them check all of your credit cards. Or tell them you can guess the last digit of any credit card number.

    Either way, you’ve got an instant source of entertainment wrapped in a ball of education!

    What do you think? Are you racing to your purse right now to check your cards? Share your thoughts in the comments.

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  • Adding Fractions with Cuisenaire Rods

    Adding Fractions with Cuisenaire Rods

    Christine asked me via twitter for some resources for Cuisenaire Rods and teaching fractions.

    Of course I can’t pass the opportunity up to do some fun things with my rods!

    Christine, I hope this helps. Let me know what’s next.

    Anyone else? What would you like to see done with fractions and/or Cuisinaire rods?

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  • A Teacher Remembers 9/11

    A Teacher Remembers 9/11

    U.S. Navy photo by Photographer’s Mate 3rd Class Ramon Preciado (Public Domain)

    Written on September 11, 2011

    Ten years ago today I learned about kids. Not that I didn’t know anything about them before. But I learned a great deal in one day because of the horror that took the U.S.

    I was teaching at a high school – something I did for about 6 months – and doing a fine poor job of it. I had taught almost ten years of college math and was struggling with the concept of discipline and lecture – simultaneously.

    The downright creativity of those guys was amazing – they could come up with the most ingenious ways of conning me into stuff. They were brilliant!

    We were in Algebra when I read the news.

    The email from the principal came through with an exclamation mark denoting high priority. I didn’t pay much attention to those flags because I didn’t have a whole lot of respect for her – she treated children and teachers alike, as if we were 2nd class citizens to be disciplined for rules that seemed to have no basis.

    So my class went clueless for the hour. It wasn’t until the next class arrived that I learned something was up.

    I headed back to the email – perhaps this time there was a wolf.

    Sure enough, the super creepy email was there. Hard to wrap my brain around. Especially since I had never been to New York and hadn’t a clue what the World Trade Center Twin Towers were.

    I went to the library during my off period and watched the subsequent disasters unfold.

    And I watched the students’ reactions.

    When I first started teaching there, I was very cautious in listening to other teachers who labeled certain kids as “bad.” In fact, I started to favor the students that had earned that moniker. How can you be “bad” at 14? Maybe on your way to bad, but certainly not there yet!

    And sure enough, one of my favorite students (with a “very bad” label) was the most devastated by the tragedy. “Why?” he asked with tears in his eyes. “Why would anyone do that? I just don’t understand.”

    No doubt the “good” kids who blew it off and make terribly inappropriate jokes did so out of personal protection.

    It was strange to see the various reactions of all the different kids. And many of them were not what I would’ve expected.

    There are many things I’ll never forget.

    Indeed this was a moment, a day, and ten years that I’ll never forget. And most importantly, I’ll also not forget how children take things.

    Kids are people too. And they aren’t bad. None of them.

    If you’re a teacher, know this. If you’re a parent, remember this.

  • Counting with Big Numbers

    Counting with Big Numbers

    Last night I had the privilege to meet and teach Eddie*, an ESL student from Mexico, at Literacy Advance of Houston. He was there to learn in the “Math and Your Life” class, as part of the “Math and…” class series.

    I didn’t realize I was there to learn too.

    I walked in prepared to discuss just about anything math related. And I’m glad that was the preparation I did.

    Eddie was interested in something that I’ve long struggled with. And I’m guessing many children struggle with it, too.

    In English, the number 1600 is pronounced both as sixteen hundred and as one thousand six hundred. I still get these mixed up. Not when I stop and think about them, but when I casually and quickly throw them out.

    Husband is often stunned when I tell him I saw a new suburban at the low low price of thirty-five hundred dollars. Of course I mean thirty-five thousand dollars!

    It’s not just me, I guess.

    I wonder how many other grown-ups still struggle with this. And how often we neglect to teach this to children.

    We are quite accustomed, and comfortable, with teaching our youngsters to count from 1 to 10. Were amazingly proud when we can get them to count from 1 to 20.

    Is that enough? Based on my conversation with Eddie last night, no.

    Teach them skip counting with hundreds!

    Why not use the 1-20 model with hundreds? Like this:

    one hundred
    two hundred
    three hundred
    .
    .
    .
    eight hundred
    nine hundred
    one thousand
    eleven hundred
    twelve hundred
    thirteen hundred
    fourteen hundred
    .
    .
    .
    nineteen hundred
    two thousand
    twenty one hundred
    .
    .
    .

    Teach them all sorts of counting!

    I suggested in this article to count with your children by fractions. It never occurred to me to count by giant numbers.

    What other ways should we teach children to count? Share your ideas in the comments.

    *”Eddie” is used as a variable – i.e. his name has been changed because I didn’t ask his permission to talk about him.

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  • Back to School Math Clothes

    Back to School Math Clothes

    For many across the  world, today is the first  day of school. For after schooling families, or blended homeschoolers going to a co-op,  you’ve probably been shopping for new clothes for a few weeks. For those in areas that offer tax-free back-to-school weekends, you no doubt have taken advantage of that. Even if you unschool on a sailboat hopping around the coast!*

    And why should the children have all the fun? Why not do a little back-to-school shopping of your own?

    And of course, don’t just buy any clothes, buy math clothes!

    Math accessories dress up a business or formal look.

    At a fancy business meeting, or a full tilt gala, show your  affinity for math with your jewelry. This Fibonacci sequence necklace is a beautiful addition to the little black dress or business suit:

    Notice the Fibonacci sequence: 1, 1, 2, 3, 5

    This artist is working with me to create some really neat Fibonacci earrings and matching bracelet. We’re also working on other patterns and concepts for jewelry that says, “Math is cool, and it’s pretty too!”

    Business casual means t-shirt with a blazer.

    My favorite outfit is a math T-shirt with a blazer over the top. I wear some slacks and modest heels and I’m ready to take on the world. Here’s a T-shirt that I found that’s on its way to me now:

    This “obtuse” shirt is created by Matt at ExBoyfriend Collection (now BoredWalk), who is generous enough to give one to me! I’ll post a photo in full dress when it arrives.

    It reminds me of what my Ma used to tell us: “Quit being so obtuse!”

    Matt creates other math t-shirts too! We’re looking at collaborating on some – so keep your eyes peeled.

    Take it to the limit with casual wear.

    You can also wear a t-shirt as just a t-shirt, with shorts or capri pants.

    This infinity shirt is from Mike who publishes MathFail, Spiked Math Comics and Math Shirts.

    What’s your favorite math outfit? Are you hitting the stores for yourself this back-to-school season? Share with us in the comments!

    * BTW, that’s my homeschooling dream – on a sailboat, unschooling around the coast!

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  • The Math Textbook Game

    The Math Textbook Game

    Yesterday I mentioned how textbooks created the first flipped classroom by playing games with the content for profit. I ran across this just now:

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  • The Flipped Classroom – Getting Back to Traditional Education

    The Flipped Classroom – Getting Back to Traditional Education

    Years and years ago there was a math education model. It went like this:

    Children would read a section or chapter of a textbook the night before class. They would come to school the next day ready to ask questions and do hands on practice with a teacher close by to help.

    This was a “normal” classroom situation.

    Over the course of many years, textbook publishers have squeezed more and more topics into textbooks. Thus, they have squeezed more and more detail out. Which has gotten rid of much of their value.

    As math texts had their details extracted to fit more topics, children began having difficulty comprehending them. Even if they attempted to read the section the night before, the teacher would have to fully explain it during class the next day.

    Thus the first flip happened!

    Kids gave up altogether on trying to read math textbooks. They soon realized that the teacher’s instructions to “read the section” as homework was just an empty request. The teacher would explain all of it the next day anyway.

    This model, the first flipped classroom, has sustained for quite some time.

    Enter web-based video.

    Fun to watch and easy to rewind, online videos allow kids to flip back the model. Because videos aren’t regulated, nor monetarily driven, anyone can make them – including people who are really good at it.

    Yes, a pair of teachers at Woodland Park officially did the first flip. But check out what kids have done without teachers. They found Cousin Sal’s videos before it was ever <cue music> Khan Academy.

    They inherently knew that there could be more and that there was a better way to learn. They started watching videos at night after they didn’t get everything they needed during the day. And they started going to school the next day asking questions of their live teachers: “I saw this video on YouTube and he did it this way… can I do it like that?”

    We didn’t flip anything.

    Yes, we think we’re really clever and have this great “flipped classroom” model. Guess what? We adults haven’t done squat – we’re just writing about it and making cute infographics.

    Let’s give credit where credit’s due, shall we? Textbook companies drove the first flip. And kids are driving this one.

    Not us.

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  • [50 Word Friday] The Original Flipped Classroom

    [50 Word Friday] The Original Flipped Classroom

    Years ago, kids learned from a textbook at home and came to class the next day prepared to do hands-on practice.

    Since then, textbooks have minimized details to maximize topics, rendering them useless.

    Students required the model to flip to school learning and home practice.

    Luckily, it’s getting flipped back.

    Learn more about 50 Word Friday here.

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