Divisibility Rules

math224x150
Math is a beautiful thing. I was showing my third grade and sixth grade sons the nifty thing about the multiplication facts for the number nine. If you write them down, starting at 9 times 1 and work your way up the table there is a curious thing that occurs. The one’s place of the product decreases by one as the 10’s place increases by the same. 9, 18, 27, 36… My wife noticed that the sum of the digits was always 9. Working together we tested our little theory that maybe all numbers whose digits sum to a number divisible by 9 are in fact also divisible by 9. With a suggestion from our sixth grader, we calculated the sum of 123456789’s digits (45). Nice. Totally divisible by 9. 123456789/9=13717421. Fantastic. This worked with 3 as well. Simple since 9 is divisible by 3.
After they went to bed, I needed to look this up and see what other nifty rules of divisibility that there might be. That could give me something else to teach them later. Without getting into the Math-iness of modulo arithmetic there are indeed many different variations of determining the divisibility of a number by another number without having to perform the division out right. We already figured out the 3 and 9 version ourselves. I think everyone who can multiply or even skip count knows the rules for 2, 5, and 10 without much thought. If the one’s digit is even you can divide the number by 2. If the one’s digit is a 5 or 0 (zero) you can divide it by 5. If the one’s digit is a 0 (zero) you can divide it by 10. Easy-peasy. What came next was so very interesting that I thought writing this blog post would be fun.
1, 2, 3, 5, 9, 10 – These are easy rules to remember. We can use these rules together to figure out other numbers of divisibility with the combination of one of these. As an example, to figure out if a number is divisible by 6 we can determine if the sum of the digits are divisible by 3 and the one’s digit is even. Since, 2 x 3 = 6, the number would be divisible by 6 if it is divisible 2 AND 3 together. We have other missing divisors (4, 7, 8) before we get to 10. 4 is pretty simple. Take the last two digits if they are divisible by 4 so is the whole number. There are some really complicated rules for calculating the divisibility of 7 that uses recursive operations. A little complicated for my grade-schoolers and quite frankly might be easier to just grab your calculator. 8 is nice because you only have to evaluate the divisibility of the last three digits.

For some in-depth information check out the site Cut the Knot. There is plenty more the math gobbledygook there to make your proofs if you need them.

Happy New Year! 19 days ago.

NewYear2015Since it is the new year and you are supposed to have a resolution/goal/something to fail at, I have set a couple for myself this year. Physical resolutions are great to fail at. Oftentimes, people are done with theirs before even today. My physical resolution for the year is to get into better shape. In order for a resolution to have any real teeth, it needs goals. My goals to make a better me physically – I will perform a single pushup, crunch, and squat for each day of the year, compounded. It is the 19th today and I did the 19 pushups, crunches, and squats this morning. I also added a few chin-ups. It doesn’t sound like a lot. But, by the end of the year I should be doing well over three hundred a day. Look out Mr. Universe.

Mental resolutions are harder to do. At least I think so. It is easy enough to say, “I am going to write a novel by the end of the year.” or “I will write four publishable short stories by the end of the year.” Each of these are indeed nice resolutions. They both have something that is attainable, measurable for success, and you can have goals for them. To measure that success, I want to set a goal similar to the physical resolution. Something easily attained and I can build it up. Words, pages, or hours per day. This is where it gets harder. I can write for hours, and at times, only get a few hundred words down on paper. Even then they can smell worse than the laundry I forgot to throw into the dryer the day before. Words per day seems too hard for me to maintain. Pages per day would be in the same place as well. That really leaves hours per day. So, I have set a goal to write a minimum of 1 hour per day increasing that by an additional one half hour per month. That should be easy to attain and I will gradually increase the writing load minimum. Granted, I will likely write for more than an hour each day, but that minimum will keep me in line and off the couch.

I have taken some time over the last few months researching a story or two, writing a couple, and doing what I can to learn the craft of writing fiction. I read three ‘self-help’ books on the craft of writing. Reading other writers’ blogs is interesting as well. The general gist is that every writer has a different method, procedure, or psychic process that they employ. Mr. Cleaver, in “Immediate Fiction,” drives home something that I think centers in good writing. “Want, Obstacle, Action.” This is probably the title of a 101 class in a Fine Arts school that I didn’t attend. I have heard it a few different ways substituting those three words with some variation of synonym from all different kinds of writers trying to tell us how to write.

Overall, I have found that writing is a bit like chess. It takes a relatively short period of time to get the movement of the pieces, order of operations, and a few strategies. However, it is a lifelong pursuit to a perfect game that one may never achieve. Oh, but what fun it is to play!

Here are a few websites/blogs that I have ran across that might interest you:

The Grinder – A free listing of paying markets for submitting your short work. You can set up a login and track your submissions if you wanted to.

Paper Beats World – Writer blog by Nicole Ford. She recently had a flash story published on Every Day Fiction titled Favorite.

Happy New Year, and keep writing and reading.

Read. People. Read.

I wanted to write something real quick before I am too caught up in the eating of the turkey, dressing, pie, and more pie. Before the tryptophan coma (I know, I read it already) takes over my existence, until the last of the leftovers can be consumed. Plus the pie. Don’t forget the pie.

Friday, I read to some very eager third graders. I forced them to listen to me read poetry. Ah, the horror! I tell you what, those little ones are quite smart. The questions that they asked for context and clarity were outside my expectations. I read two poems from the former Poet Laureate (2001-2003) Billy Collins titled “Litany,” and “The Country.” I find both quite fun to read. Letting the guys and gals of this third grade class interpret them was even more enlightening for myself than I thought it would be.

The world is so full of coma inducing media for children it is refreshing to see that these third graders could step out from the pretty lights and pictures and use their minds to express something as abstract as poetry. Read to your children. It doesn’t have to be as obtuse as poetry can sometimes be. Although, Billy Collins is quite funny. You can read them anything. There are stories written every day that can provide so much entertainment for you and your child. And believe me, they can understand more than you could imagine.

Read. People. Read.

Happy Thanksgiving!

The water is fine…

Red Hare Long Day Lager
Me and my beer.

I am sitting at my desk finishing off my beer. A local brand, Red Hare Brewing Company, here in Marietta, Georgia. Long Day Lager – Perfect for the situation. I am selling my house, doing this writing thing, making sure the children get to school (and back), and trying to find myself in social media. Hell, I am not even sure I know what that really means.

I have been working on this whole social media thingy-do the last few months. Quite frankly, I understand only minor portions of it. At the present time, 11:54PM EDT October 9, I have 172 followers and I am following 330 Twitter accounts. I haven’t tried to touch anything else really.

There are a lot of interesting people out there. I have been focusing on the writing crowd. Those are the ones I want to understand. What is working for them and what isn’t.

I have been looking at the number of Tweets that folks can put out. Social media is like swimming in a giant pool with a bunch of those shiny little fish. They all look just like you and flit about in the water real fast. The Twitter page will update you on the number of Tweets you missed while you were trying to read some of the ones displayed in your timeline. I timed it once. In less than 10 minutes I missed reading over 200 Tweets. Like anybody can read that fast or would they really want to. Some of the tweets are just downright silly.

“Hey, I just stepped out on the porch. It’s raining!”

“Did you know if you flush the toilet, the water just whooshes right out of there.”

“Hey! Read my book. It is just fantastic! Somebody else thinks so too!”

Then you have the guy who thinks that he can only have friends if he ReTweets, I don’t know, a thousand Tweets in a day. If a real person can spend that much time performing the thumb or wrist gymnastics to get it done, when do they write their own fiction? Thank goodness for the Mute function.

I suppose that Tweeting is like blogging. You get out of it what you put in. I do like the interaction with my “peers.” I don’t know that I have any ability to keep up with what hardly any of them are saying. It is still fun to have a lookie-lou every now and again and see what everyone is going on about.

I think that the Twitter timeline reminds me of the scene in Poltergeist where Carol Anne is staring at the television. Noise. If you stare at it long enough, though, stuff just starts popping out at ya.

Keep writing.