I couldn’t resist sharing this happy little math gif. Mathematically speaking, it makes no sense, but it’s still sweet.

Happy Valentines Day!

The post Happy Valentines Day! appeared first on Math for Grownups.

Can you explain what you do for a living?

Well, throughout the year, my main job is to oversee a large toy production facility at the North Pole. This includes supervising thousands of elves, who are responsible for toy manufacturing, as well as management of the reindeer stables, grounds work, sleigh maintenance and other smaller details.

But my main responsibility is only on one night of the year. On Christmas Eve, I pilot a large, flying sleigh, driven by eight reindeer and Rudolf, throughout the world to deliver presents to all good boys and girls. It’s a big night, and I usually take off the entire month of January to recover!

When do you use basic math in your job?

There’s a surprising amount of math involved in my work. These days, the naughty-and-nice list is in a database. A sophisticated set of formulas help me map out my once-a-year trip, which determines how the sleigh is packed. If Los Angeles gifts are on the top of the pack when I land in New York City — well, that’s a big problem.

I also need to manage my time, since I have so little of it that night. The different time zones help me stay a little ahead of the clock in most cases, but I sometimes have to do some on-the-spot figuring when weather becomes a problem.

But the real math is in the sleigh. Much like an airplane pilot, I must maintain a steady speed and take into account things like wind and visibility. The elves have helped equip the sleigh with state-of-the-art equipment, like gauges for altitude and speed. However, there have been some times when I’ve need to apply distance/speed/time ratios on the fly.

Do you use any technology to help with this math?

Absolutely. As I mentioned, we depend heavily on databases on the North Pole. These are housed in a large server, allowing us to manage our manufacturing quickly and easily. If a formula needs to be changed — for example, we need to greater ratio of purple bicycles to red bicycles — that alteration can be made in the database and applied throughout the facility. It streamlines the process considerably.

And I couldn’t fly to as many houses as I do today without my computerized dashboard in the sleigh. Each year, it’s calibrated to the specific weather conditions that are expected and even the current weight of the reindeer. Being able to customize these variables means making the most of those 20 hours that I’m in the sky.

How do you think math helps you do your job better?

I’m sure many people have said this: I couldn’t do my job without math. From the elves’ payroll to the naughty and nice list, every point of this whole operation hinges on how well we’ve done the math.

How comfortable with math do you feel?

I’d much rather talk to a child about what he or she wants for Christmas than sit down and solve a bunch of algebraic equations. But I’ve learned that in order to accomplish all that I do, I need to do some computing, too. I feel pretty comfortable with math, but it’s not my favorite thing in the world.

What kind of math did you take in high school?

School was a lot different way back then. You have to remember, I’ve been around for a long, long time! Heck, calculus wasn’t even invented yet, and forget about the calculator! But I did fine with the little bit of math I did take in school.

Did you have to learn new skills in order to do the math you use in your job?

When you’ve been in a job like mine for this long, you definitely have to pick up some new skills. The biggest changes have been technological. And once computers came on the scene, all of my operations had to be redesigned. I’ve even brought on some elves who are experienced with math modeling, so that we can stay ahead of any climate changes that will certainly affect our work. They’re developing up several models now with regards to the North Pole itself.

Thanks so much to Santa for taking time out of his incredibly busy schedule to answer a few questions. Happy holidays to everyone! In honor of the season, I’m going to take the rest of the week off. I’ll see you back on Monday, December 30, when we’ll kick off a really cool month designed to help you meet a special New Year’s resolution: brushing up on your basic math skills.

The post Math at Work Monday: Santa Claus appeared first on Math for Grownups.

And so, I bring you Christmas by the Numbers, a round up of interesting statistics about this huge holiday.

93: Percent of Americans (in 2008) who say they celebrate Christmas

81: Percent of Americans (in 2008) who identify with Christian faith

$427 million: Predicted sales of Christmas cards in 2012

4.1: Percent that holiday sales are expected to rise in 2012 over the previous year

12: Percent that online holiday sales are expected to rise

625,000: Predicted number of seasonal workers expected to be hired this holiday season.

25-30 million: Number of real Christmas trees sold in the U.S. each year

7: Average growing time (in years) of a six- to seven-foot tall Christmas tree

4,000: Number of Christmas tree recycling programs across the country

749.51: Dollars expected to be spent on gifts, decor and cards by the average holiday shopper this year

60: Percent of holiday shoppers expected to “self-gift”

1: Rank of gift cards in list of popular Christmas present requests

10: Percent chance of a white Christmas in my city (Baltimore, MD)

Any statistics that you’d like to see? Share your ideas in the comments section. Happy holidays!

The post Christmas by the Numbers appeared first on Math for Grownups.

So, if you’re still looking for a little giftie or two for the geek — or geek-lover or geek-wannabe? — in your life, here are some ideas.

Mathletic Department Hoodie

I am not an athlete. Not by any stretch of the imagination.  But even I would wear this hoodie. It’s the perfect mix of geek and cool. Well, at least I think so.

From Cafe Press.

Math Love Onesie

It might take you a moment to see the beauty of this design. I’ll wait.

Get it? Even if you can’t follow the solution to from start to finish, the last line is perfection. (Must speak internet.) And while you’re baby is sporting this fashionable accessory, you can review solving inequalities.

Made by Skyhawk Press, Monterey, Cal. Available on Etsy.

Number Cookie Cutters

Because how else can you make a π pie? I have a set like these, and while they’re terrific for really geeky cookies, they’re also great for making cute kid-party sweets — Like a bunch of 3s for a three-year old’s party. They’re also handy when you need number “stencils.”

Available at Barnes and Noble (order online and pick up at the store).

Tiffany & Co. Infinity Bracelet

Splurge for the platinum with diamonds or stuff her stocking with a more moderately priced bobble in sterling silver. Either way, you’re telling her that you mean forever in a delightfully geeky way.

Available at Tiffany & Co.

Obsessive Chef Cutting Board

We all have one in our families or among our friends: the home chef who cooks with the precision of a surgeon. And finally, here’s a cutting board they can truly appreciate. With guidelines for julienne, chop and mincing — and even including curves and bias marks — veggies have never been so perfectly prepared.

Made by Fred & Friends.

Consul the Educated Monkey Calculator

This has to be my very favorite find of the holiday season. A reproduction of a 1916 toy created by William Robertson, this little piece of tin can find the product of two numbers in the shake of a tail. Give it to a particularly precocious child and ask him or her to figure out why it works. (Hint: It’s all about the triangles.)

Available at local gift shops and online.

Need more ideas? Check out last year’s list, which offers ideas specifically for kids.

And if you’re in the market for something funny and useful, check out my book, Math for Grownups, designed to ease the fears and pain of even the most resistent math-phobe. Promise. (Available online, at local independent bookstores and Barnes & Noble.)

Do you have gift ideas to share? Please post about them in the comment section. (I still have a few things to pick up myself!)

The post Last-Minute Gifts for Geeks and Not-So-Geeks appeared first on Math for Grownups.

I don’t share this story to toot my horn. Plenty of people do as much or more than that each year. And I’m guessing their motivation is the same is mine — it feels good to give.

At the same time my math brain loves some guidelines. I grew up Lutheran, and I was expected to tithe 10% of my allowance. It was a great practice to get into, but now that I’m not a tithing church-goer, I miss having a formula. How much giving is “enough”? How can I know if I’m pushing myself enough?

Last year, I came across Peter Singer, who developed a really wonderful set of formulas based on a variety of different incomes. I wrote about it last fall, and I thought I point you to it today — in case you didn’t see it or need a reminder.

The Math of Generosity

No matter what holiday you celebrate in December, the month has traditionally marked a time for charitable giving.  The weather is growing colder in some areas, making it much tougher on the homeless.  The end of the year is creeping up, and with it the deadline for tax exemptions for charitable giving.  And holiday cheer often means counting our blessings and remembering those who are less fortunate.

Yes, December is the time for giving.  But how much is enough? And what is too much?  As we attempt to balance our own needs (especially in these difficult economic times), many of us struggle with our own sense of guilt and generosity. Read the rest of this post.

Do you have a formula for developing your yearly contributions? Share it — or your thoughts about using math to make charitable giving decisions — in a comment.

The post Tis the Season to Give Generously: Do the math first appeared first on Math for Grownups.

In honor of Hanukkah, I bring you some numbers that are important to this holiday. Enjoy!

6.6 million: Estimated Jewish population in the U.S. in 2011

2.1: Percent of the entire U.S. population in that year

8: Days and nights of Hanukkah, and a number of days that a one-day supply of oil miraculously burned during the time of the rededication of the temple by the Maccabees.

25: The day of the Jewish month of Kislev, on which Hanukkah is celebrated each year

9: Including the shammus — or service — candle, number of candles in a menorah

3: Number of blessings recited during the first night of Hanukkah

2: Number of blessings recited during all other nights of Hanukkah

30: Minimum number of minutes the Hanukkah candles should burn each night

44: Total candles lit (including the shammus) overall eight days.

4: Number of Hebrew letters inscribed on a dreidel

92: Approximate number of years that American chocolatiers have been making chocolate gelt.

4: Number of potatoes required for Debbie Koenig’s most delicious latke recipe. (My favorite one I’ve ever tried!)

19: Number of celebrities mentioned in Adam Sandler’s Hanukkah Song.

2: Number of those who are not Jewish

What other numbers are important to Hanukkah? Share them in the comments section.

The post Hanukkah by the Numbers appeared first on Math for Grownups.

Ah, the cookie exchange!  What better way to multiply the variety of your holiday goodies.  (You can always give the date bars to your great aunt Marge.)

The problem with this annual event is the math required to make five or six dozen cookies from a recipe that yields three dozen.  That’s what I call “cookie exchange math.”

Never fear! You can handle this task without tossing your rolling pin through the kitchen window. Take a few deep breaths and think things through.

To double or triple a recipe is pretty simple — just multiply each ingredient measurement by the amount you want to increase the recipe by.  But it’s also pretty darned easy to get confused, especially if there are fractions involved.  (And there are always fractions involved.)

The trick is to look at each ingredient one at a time.  Don’t be a hero!  Use a pencil and paper if you need to.  (Better yet, if you alter a recipe often enough, jot down the changes in the margin of your cookbook.)  It’s also a good idea to collect all of your ingredients before you get started.  That’ll save you from having to borrow an egg from your neighbor after your oven is preheated.

Read the rest here — and you’ll avoid fractions-related, messy kitchen mistakes.

While you’re at it, check out this interview I did with fantastic candy-maker, Nicole Varrenti, owner of Nicole’s Treats. (I love her chocolate mustaches, personally.) It shouldn’t be any surprise that she uses math daily.

Finally, if you have some holiday-related math questions, would you mind sharing them with me? What trips you up — mathematically — at this time of year? Comment below!

The post Time for Holiday Cookies — and Fractions appeared first on Math for Grownups.

391: The number of years since the first Thanksgiving

90: The estimated number of Wampanoag tribe members who attended the first Thanksgiving

1789: The year of the first “national day of Thanksgiving”

40: The number of years that Sarah Josepha Hale advocated for an annual, national Thanksgiving holiday

254 million: The number of turkeys expected to be raised in the U.S. in 2012

6: The number of “home economists” who were hired to answer 11,000 phone calls for the Butterball Turkey Hotline‘s inaugural year in 1981

50: The number hired to answer more than 100,000 calls last year.

165: The number of degrees of a safely cooked turkey, according to the Federal Food and Drug Administration (FDA)

768 million: Projected number of pounds of cranberries expected to be produced in the U.S. in 2012

50: Percent increase in plumber calls and visits on the day after Thanksgiving, over any other Friday of the year

43.6 million: Number of Americans expected to travel more than 50 miles during the 2012 Thanksgiving holiday

90: Percent expected to travel by car

25: Number of balloon floats in this year’s Macy’s Thanksgiving Day Parade

How are you spending your Thanksgiving holiday? What math is involved? Share your responses in the comments section.

The post Thanksgiving by the Numbers appeared first on Math for Grownups.

After years of this back-and-forth, I’ve realized one important few thing: sometimes DIY is more expensive — in money and time. That’s why I included the following in my book, Math for Grownups. Yes, the example is based on my own, personal experience, except that the ending turned out differently. (The obscure character? Luna of Harry Potter fame.) Had I really thought it through before heading to Joann’s Fabric, I would have saved myself some cash and a lot of time.

Rita loves Halloweʼen, and she loves making her kidsʼ costumes. This year, her 10-year-old daughter has requested a velvet-like cape and gown so that she can dress as some obscure character from her favorite novel about magical kids.

The pattern Rita is using calls for 7 yards of fabric, 2 fancy fasteners, and 3 yards of fringe. Looking at the Sunday circular for the local fabric store, she sees that crushed panne velvet is on sale for $2.99 per yard and the fringe is priced at $4 per yard. Rita guesses that the fasteners are about $5 each. To estimate her costs, she adds everything together:

(7 • $2.99) + (3 • $4) + (2 • $5)

(In case you lost track, that’s 7 yards of fabric at $2.99 per yard, 3 yards of fringe at $4 per yard, and 2 frog clasps at $5 each.)

$20.93 + $12 + $10 = $42.93

A terrifying price!

Rita is starting to think that a trip to a thrift shop might be a better investment of her time and money. Sometimes doing it yourself just isn’t worth it.

Do you have any scary costume stories? How have you learned to save money while DIY and celebrating Halloween?

The post Boo! Scaring up savings at Halloween appeared first on Math for Grownups.

And the rest of us? For the most part, tonight marks a very strange annual tradition here in the U.S.: going door to door in costume, asking for free candy. To mark the occasion, I’ve collected some scary statistics about the night of tricks and treats. Read at your own risk! Bwa-ha-ha-ha! (Um… that’s my attempt at an evil laugh.)

170 million: The number of people who plan to celebrate Halloween in the U.S. (National Retail Federation)

$79.82: The average spent on costumes, decorations and candy this year. (National Retail Federation)

$113 million: The total value of pumpkin crops in the three top pumpkin-producing states (Agricultural Marketing Resource Center)

1,818: Number of pounds weighed by the largest pumpkin on record. (Guinness World Records)

15.2: The percent of costume ideas that come from Facebook. (National Retail Federation)

15.1: The percent of people that will dress their pet in a costume. (National Retail Federation)

0: The percent of pets that enjoy this tradition. (Just a guess)

6: Number of times I went trick-or-treating as a “hobo,” because I was too lazy to do much else. (Personal data)

268: The population of Skull Creek, Nebraska — named for “A LOT” of buffalo skulls and bones found in a nearby creek. (U.S. Census)

1690: The number of pieces of candy that will fill an average-sized pillow case. (www.myscienceproject.org)

41: The percent of adults who admit eating candy from their own candy bowl between trick-or-treaters. (National Candy Association)

90: The percent of parents who admit stealing from their kids’ trick-or-treat stash. (National Candy Association)

99.9: The percent of parents who actually steal candy from their kids’ trick-or-treat stash. (Just a guess)

30: The percent of kids who sort their candy before digging in. (National Candy Association)

0: Number of kids who would rather get a toothbrush than candy, while trick or treating. (Just a guess)

Happy Halloween, everyone! Just one last word of warning: Watch out for the zombies. (Here’s how math can help you plan during a zombie apocalypse.)

What are your Halloween plans?

The post Scary Statistics: Halloween by the numbers appeared first on Math for Grownups.