My Prime Factorization T-Shirt Shop Is Ready!

My Prime Factorization T-shirt Shop is ready!

Now, the motivation was that when the math community found out about my Prime Factorization Sweater, many commenters said I should make a T-shirt. I “happen” to have several of the charts already created in Word, because I’ve written a children’s book about using these ideas to learn about other mathematical bases and make cyphers and patterns using the mathematical principles. So I used two of those charts to make a shirt. But I did want to see if the colors came out distinct enough before I offered it for sale.

Monday night, the shirt I ordered arrived, so I wore it to work yesterday:

And here I am among the Math books:

On the back, as with the sweater, I’ve got rows of 8, so you can see that the patterns change.

Now, there were two things I wasn’t quite happy about with the shirt.

First, one thing I was happy about was that the colors came out exactly as they looked when I printed out the charts. However, that was also the first thing I was not happy about. The blue shade for 2, on my computer screen, is nice and bright and easy to spot. On the print-out, and on the shirt, it looks much darker.

The second thing I was unhappy about was that the numbers were blurry. This was because I hadn’t been able to save my Word table as a jpeg file. My son came up with the solution of taking a screenshot and merging the two pictures into a jpeg. It was good enough, but I really noticed the little imperfections.

Then, at work, wearing the shirt, I had a brainstorm. Surely in publisher, you can turn files into jpeg files? Sure enough! So yesterday evening I went home, opened my book manuscript, and pasted the prime factorization table into publisher. It worked! My test shirt hasn’t arrived yet, but I’m confident the numbers will be more clear.

While I was at it, I changed the colors, and lightened up some factors that are used several times in the chart, particularly the blue for 2. Since my graphic looks different when it’s printed, I’ll post a picture of how the print-out looks, because that’s how it will look on the shirt:

I also added various colors, by popular demand. I now have a Caribbean Blue shirt on order with the new charts.

One other thing I should mention. For “Super Geeks” (like me), I did put rows of 8 on the back. All the charts have the numerical values under the color code, but on the back, I gave those numbers their Octal representation. So after 7 comes 10, after 10 comes 11, after 17 comes 20, after 77 comes 100, and so on. A couple times, when I was looking at the back, I forgot I was looking at the back and thought I had factored incorrectly! With the colors, you could use this as a handy-dandy way to convert from decimal to octal! (Just what everyone needs, right? But if you’re ever on an alien planet….)

I do like the way the two charts with the same colors show how the patterns change. Particularly look at yellow (5). In the decimal chart, because it’s a factor of 10, it lines up. In the octal chart, because it’s relatively prime with 8, it does not line up.

So, I’m looking forward to my new shirt coming in! And I do feel ready to offer my shirts for sale!

The URL is

Sonderling Sunday – Escape from the Ruby Palace

It’s time for Sonderling Sunday! I’m on Chapter Four, Part Three in my use of The Order of Odd-Fish and Der Orden der Seltsamen Sonderlinge in a quest to learn how to say bizarre things in German.

We’re on page 40 in the English version, and Seite 55 in the German version. Here’s the first paragraph of the next section:

Jo and Colonel Korsakov raced down the foggy, twisty passages, searching for Sefino. The deeper they plunged into the palace, the thicker the clammy clouds of insecticide became, until they had to hold handkerchiefs to their noses to breathe.

Auf Deutsch:

Jo und Oberst Korsakov rannten durch die leeren, verschlungenen Gänge und suchten Sefino. Je weiter sie in den Farbenpalast vordrangen, desto dichter wurde die verdammte Wolke aus Insektiziden, bis sie sich Taschentücher vor die Nasen halten mussten, damit sie Luft bekamen.

I know I’m getting better at German from this process, because nothing about that passage surprised me. However, I’ll make some observations.

I know we’ve mentioned this one before, but it’s still fun to say. “twisty” = verschlungenen

“plunged” = vordrangen

“clammy clouds” = verdammte Wolke (No, they’re not swearing. It’s damp.) I have to admit that the English for that one sounds better. (What can I say, I like alliteration.)

You know, when I typed “handkerchiefs” I thought that must be a word of German origins, being a portmanteau word, and since I know “hand” itself comes from German. And doesn’t “kerchief” sound like it’s probably of German origin? But the actual German word is even better. Taschentücher means “pocket cloths.” Isn’t that perfect?

Going on, I’ll list some interesting words:

“greenhouse” = Gewächshauses (“plant house,” and “plant” is same root as “to grow”)

“prodding” = piksten (like “poke,” I think.)

“pleased with himself” = selbstzufrieden (for once, the German is shorter!)

“multiply” = vervielfachen (“for many times”)

“duties” = Pflichten

Here’s a lovely long one:
“differences” = Meinungsverschiedenheiten (“opinion differences”)

“tender recesses” = zarten Gliederungen (“tender outlines”)

“inconveniences” = Unbequemlichkeiten (Funny. I was investigating this word. As did not surprise me, bequem means “convenient.” More interesting: bequemlich means “sedentary.” I guess inconveniences are things that don’t allow you to be sedentary.)

“barked” = blaffte

This one uses a funny idiom in place of an English one:
“Jo knew the twisting maze of the ruby palace by heart.” becomes Jo kannte das verschlungene Labyrinth des Rubinpalastes wie Ihre eigene Westentasche.

wie Ihre eigene Westentasche means “like her own vest pocket.”

“wide-brimmed” = breitkrempigen

I like the word at the end of this sentence:
Das Faktotum packte Ken Kiangs Hand und schüttelte sie wie einen Pumpenschwengel.

That’s translated from: “Hoagland Shanks grabbed Ken Kiang’s hand, shaking it vigorously.” wie einen Pumpenschwengel means “like a pump handle.”

“suffocating” = erstickend

“double doors” = Flügeltüren (“flying doors”)

“glory of battle” = der Pracht der Schlacht

“whacking him with canes, walkers, and wheelchairs” = Sie schlugen mit Gehstöcken, Krücken und Rollatoren auf ihn ein.

A new word for “crop duster” is Sprühflugzeug. (“spray flying thing”)

And that gets us through Chapter Four! Summing up, I think my favorite words of the day are Pumpenschwengel und der Pracht der Schlacht.

Happy Sonderling Sunday! Do something today to make yourself selbstzufrieden.

Prime Factorization Swatches

I finished three swatches and decided on how I’m going to approach my new Prime Factorization Scarf.

First, I tried garter stitch. It’s a reversible stitch, and I thought it would work for the scarf. No pun intended, I thought I’d begin with the primary colors, since they are clearly “red,” “blue,” and “yellow.” Here’s how that swatch turned out:

The colors do stand out in this version. Black is 1, the background color. The pattern starts on the left. 2 is red. One ridge clearly stands out for the factor. When you get to 1 again, you stop multiplying and start a new number. Primes will always be one ridge. Next is 3, which is blue. Then comes 4, clearly showing as two ridges of red, 2 x 2. Then black, so you start a new number. Then comes 5, a new color, yellow. Then black. Then we have a ridge of red with a ridge of blue, 2 x 3 = 6. A ridge of black. Then 7, a new color. Black. Three ridges of red, 2 x 2 x 2 = 8. Black. Two ridges of blue, 3 x 3 = 9. Black. A ridge of red and a ridge of yellow, 2 x 5 = 10.

What I like about this swatch? The colors pop out and clearly show how many of each factor you want.

Problems with this swatch? Well, I completely forgot that garter stitch with colors is not reversible. Here’s the other side:

The garter stitch pattern would work great in a sweater, where you only see one side. But a scarf is better when it’s reversible, since it’s not easy to keep only one side of a scarf showing.

One other problem was that I didn’t like the colors. In the picture on the web, the red looked like a pretty cherry red. In real life, it was so bright, it almost glowed in the dark. Next to black, it feels glaring.

So I decided to experiment with the colors I think are the prettiest of all the ones in the box. After all, the color for 2 is going to get used in every other stripe. Might as well use a color I like to look at, right?

I needed to pick a stitch that would be reversible in color. I chose the Double Seed Stitch, which gives a nice textured look. You alternate two knit stitches with two purl stitches, and you do two rows that line up with each other. Then you do two rows with the stitches staggered from the first two — The knit stitches in the two top rows are lined up with the purl stitches in the bottom two rows, and the purl stitches in the two top rows are lined up with the knit stitches in the bottom two rows.

You can’t really tell the colors I used in the next swatch, but it’s a turquoise for 2 and pink for 3, yellow for 5, and purple for 7. I got happier and happier as I knitted. I think this is beautiful, and it will be the pattern I use for the scarf. Here’s that swatch:

Now, I acknowlege that it’s not nearly as easy to tell exactly where the numbers separate or exactly which factors are in the number. But it’s pretty. And I know which factors are where. And it’s completely reversible. The back looks exactly the same as the front.

I did one more swatch, to be absolutely sure I wanted to use a black background. I also wanted to see if using larger needles would make the fabric more drapey. The yarn band suggests size 8 needles, and that’s what I’d been using, and I think it would be nice for a sweater. But for a scarf, I’d like a little less firmness. So I made the next swatch with a cream-colored background and size 10 needles, but the same stitch and the same colors for the numbers. Here’s that swatch:

Yes, this combination is pretty. But I think it reminds me too much of my original prime factorization sweater, and I’m ready for something different. So I’m going to go with the black background.

So I’ve begun! I’m using Size 10 needles, a black background, double seed stitch, and 26 stitches across. (The swatches used 20 stitches.)

Oh, one more thing: I hereby resolve that I will, I WILL, sew the ends in as I go, so that I don’t have to do them all at the end, like I did with the sweater. (Sigh. The worst thing about this whole project!)

I also plan to make a black edging along the sides, to hide the carried-along yarn. I can practice on the swatches.

And while I’m knitting, my mind will be spinning with ideas for a cardigan.

Stay tuned and watch my progress! One of the fun things about it is that I can wait to choose colors as I go. I don’t even have to stop at 100….

My posts on Mathematical Knitting and related topics are now gathered at Sonderknitting.

Librarians Help! – With Learning

No sooner did I start this blog series — Librarians Help! — than the people with the really interesting questions started going to my colleagues! Seriously, the questions I took this week tended toward the routine, but I figure it’s just a small case of Murphy’s Law.

Again, I helped a whole lot of people find books, such as:
— A novel for a man to read next
— A Rainbow Magic Fairies book
— A study guide for the AP Psychology test
— Books by Daniel Amen
— Books on painting
— Books for teaching first graders about maps
The No. 1 Ladies’ Detective Agency
— Books on recycling for a preschool class

Other things were mostly routine, like booking meeting rooms and signing people up for programs, and putting books on hold. Virginia taxes were due this week, so all of us did help several people make copies of the forms. I helped someone print a page of the 1940 census. During my time in the Virginia Room it was pretty quiet this week, but in my own genealogy, I traced a line back to someone who helped found Harvard.

One of the more satisfying interactions was helping a person get a library card, and then find materials for learning English, and sign up for English tutoring.

I was called an “angel” by someone who called to see if his co-worker could get a Serbo-Croatian dictionary for a test the next day. This ended up involving checking out a reference book, but since it was for someone who works in law enforcement in a building near us and would be returned the next day, and since there is not a lot of demand for that title, I was able to make sure it happened.

As I blogged last weekend, I went to the US Science Festival on my day off and wore my prime factorization sweater. Once math geeks (my tribe!) found out about it, my site got a flood of traffic to the post where I explain how the sweater works.

But this made me think, again, about how making this sweater, to me, is something wonderfully fitting for a librarian. Because, to me, librarianship is about the fun side of learning, the self-propelled side. When I taught college math, I had to focus on trying to barrel through the syllabus before I ran out of semester. As a librarian, I can say, “Isn’t this cool?” and help provide ideas and resources for people to take off from there.

When I was a Youth Services Manager (and I will be again — some day), I did a program based on the ideas behind the sweater. I showed the math behind the sweater and explained how number bases work and how you can make codes based on that. Then we used foam shapes to make their own messages using these ideas.

It’s the same thing with spreading a love of reading. We can encourage the playful and fun side of learning. We don’t force anyone to learn anything. But we have all kinds of information available, and we’re all about helping you learn whatever you want to learn, whatever age or race or economic status you happen to fall into.

Spread the word! Librarians help!

Review of Edgar Allan Poe’s Pie, by J. Patrick Lewis

Edgar Allan Poe’s Pie

Math Puzzlers in Classic Poems

by J. Patrick Lewis
illustrated by Michael Slack

Harcourt Children’s Books, 2012. 37 pages.

I feel a tiny bit sheepish by how much fun I find in this book. J. Patrick Lewis, Children’s Poet Laureate, has parodied 14 classic poems that children may well be familiar with and has inserted… a math problem.

These problems are not particularly tricky. Though I suppose that depends on the child’s age. (There is some multiplication and division, so this is more for upper elementary grades.) At times it’s not totally clear exactly what they want you to figure out (though that is given in the upside-down answers on the next page). But the parodies are definitely playful.

Could there possibly be a better way to get a kid to do word problems for fun and without fear?

The poems, after the title, list the poem they are inspired by.

Here’s the end of “Edgar Allan Poe’s Apple Pie,” the one inspired by “The Raven”:

I ignored the frightful stranger
Knocking, knocking . . . I, sleepwalking,
Pitter-pattered toward the pantry,
Took a knife from the kitchen drawer,
And screamed aloud, “How many cuts
Give me ten pieces?” through the door,
The stranger bellowed, “Never four!”

Another favorite for me is the one that plays off a poem I love, “Us Two,” by A. A. Milne. Here’s the beginning:

Wherever I am, there’s always Boo.
Boo in the flowers with me.
The size of our garden is eight by two.
“How much wire for the fence,” says Boo,
“If it wraps all around as it ought to do?
Let’s guess together,” says Boo to me.
“Let’s guess together,” says Boo.

With some, like “Robert Frost’s Boxer Shorts,” he goes for silly. “Langston Hughes’s Train Trip” uses some trickier math. “Edward Lear’s Elephant with Hot Dog” is just a limerick.

That should give you an idea of what’s going on here. Some quite silly fun. With math!

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Source: This review is based on a library book from the Fairfax County Public Library.

Ready to Start My Prime Factorization Scarf!

My yarn arrived tonight! 26 shades of Plymouth Encore yarn (on sale at, so I can make a Prime Factorization Scarf that goes all the way up to 100!

Now, a lot of the shades ended up looking more alike than I hoped they would. But I can always hold those toward the end where they only turn up once. I also didn’t realize what large skeins I was getting — I will need to make a sweater after this, because I’m going to have all kinds of leftover yarn. But I can change the color scheme to keep it interesting.

My mission first: Decide which colors will be most dominant. I’m planning on black for 1 this time, but I’m going to swatch out some different combinations for 2, 3, 5, and 7, to decide how I like it. I was planning on red for 2, but it’s so bright — I might not want that much red in the scarf. And I really like the turquoise blue that came. So we shall see… I’ll make some small swatches before I try the actual scarf.

If anyone wants to play along and make a scarf with me, let me know! It might be a lot smarter to make this as a leftover-yarn project and use up old yarn, instead of buying all the same yarn. I wish I’d thought of that! Anyway, I will think in terms of using the yarn for a cardigan later. For now, I’m looking forward to playing with some swatches!

My posts on Mathematical Knitting and related topics are now gathered at Sonderknitting.

Review of Dodsworth in Rome, by Tim Egan

Dodsworth in Rome

by Tim Egan

Houghton Mifflin Books for Children, Boston, 2011. 48 pages.

Move over Madeline! If you’re going to take your kids to Paris, New York, London, or now Rome, you need to get these books about Dodsworth and his duck visiting those cities.

The first Tim Egan book I read was Serious Farm, and that was enough to make me love his work. The Dodsworth books are short chapter books (four in this one) with large pictures on each page, showing major landmarks, and a hilarious deadpan storyline.

In Rome, they ride a scooter, see (or don’t see) the sights, evade pickpockets, and participate in a pizza-throwing contest. Dodsworth stops the duck just in time from adding a duck to the Sistine Chapel.

I really wish I had these books when I lived in Europe. It would add some fun to take my kids to the same places Dodsworth saw, making sure they behaved better than the duck.

This is simply a fun story — a perfect choice for a child ready for chapters, sure to help them enjoy reading.

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Disclosure: I am an Amazon Affiliate, and will earn a small percentage if you order a book on Amazon after clicking through from my site.

Source: This review is based on a library book from the Fairfax County Public Library.