Math for Grownups
Tag

COOKING

Browsing
In Holidays

Cookie Exchange Math

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.

Each year, I bring cow cookies to my neighborhood cookie exchange.  What are cow cookies, you ask?  Just what they sound like: sugar cookies cut into the shape of a cow.  The spots are made of melted chocolate.  (They’re Holsteins, of course.)  And around each of their little necks, I create little (icing) wreaths with red (icing) berries.

(Why do I make cow cookies?  It’s a long story.  But I’ve been these to holiday parties for more than 20 years now.  Kids love ’em.)

The problem is that my cow-shaped cookie cutter is larger than most other, eh-hem, more traditional Christmas cookie cutters.  So, while my recipe says it yields 36 to 48 cookies, I know I won’t get that many.

So each year, I triple the recipe.  That way I have enough for the cookie exchange (5 dozen), plus some to take to my mom’s house and give away to friends.

I can’t share the recipe here, because it’s copyrighted by Better Homes and Gardens (otherwise known as the Red Plaid Cookbook).  But we can look at the ingredient amounts.  My recipe requires the following measurements of various ingredients:  1/3 cup, 2 cups, 1 tsp and 3/4 cups.

Since I’m tripling the recipe, I’ll need to multiply each of these amounts by 3. Then I can measure out the ingredients using the altered amounts.

The first three calculations are simple, but what about that last one?

The really easy way to get around this fraction is to fill a  one-fourth cup 9 times.  And honestly, if that’s how your brain works, go for it.

But if you want to, you could turn the fraction into a mixed number.  Here’s how:

Ta-da!  In only a few steps, I’ve done the simple math needed to alter this recipe.  Now, I just need to keep my fingers out of the bowl — so that I can actually bring enough cookies to the exchange.  (Honestly, I’d rather eat the dough than the baked and decorated cookies!)

What are your holiday recipe math tricks?  Can you think of other, more creative, ways to alter a recipe.  Share your thoughts in the comments section.

Read More
By
In Math at Work Monday

Math at Work Monday: Nicole the candy maker

Math is a chief ingredient in the kitchen, and those who make a living creating the sweets many of us crave during the holidays depend on calculations every day.

Nicole Varrenti is the chief candy maker and owner of Nicole’s Treats. Like many artisans of all kinds, she makes small batches by hand and ships to buyers all over the world through her Etsy shop.  Here’s how she uses math in her job.

Can you explain your job?

I hand make Belgian chocolate candy and other edible treats like granola, spoon fudge, and caramel sauce. I opened my Etsy shop in August 2008, but I have been making candy for more than 20 years.

When do you use basic math in your job?  

I use math DAILY! I need to measure ingredients for my treat recipes and weigh my products to ensure my customers receive the amount of product they ordered. I measure and weigh boxes to prepare them for shipment. Also, I triple check all my orders to make sure all amounts, charges and weights are correct. From start to finish, on one order, I use math at least five times.

Do you use any technology to help with this math? 

Of course I use old-fashioned measuring cups to measure ingredients, and a scale to weigh ingredients and packages. I use a calculator to calculate the price of my products and a computer is very useful to store spreadsheets so I can keep track of all my sales, purchases, expenses, shipping costs, etc.

Math helps to keep my business organized so I can see how I am doing on a daily basis. Without math I would be lost and would not know how my business is performing.

How comfortable with math do you feel?  

Math has never been my strong suit; in fact I had a math tutor for many years while I was in middle and high school, when I took algebra, calculus and geometry. However, since I use math on a daily basis I am comfortable with math and in my skills now.

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

All of the math I learned in school has played a role in my job at some point or another. Sometimes I have had to re-learn certain math skills or just refresh my memory by practicing a bit. The only new skill I would say I had to learn was some basic accounting since I never took an accounting class.

Nicole’s blog has gorgeous, mouthwatering photos of sweets, plus free recipes.  Visit! But first, if you have questions for her, ask them in the comments section.

Read More
By
In Holidays

Talking Turkey

I’m taking it easy this week (ahhh!), and so I’ve brought you an excerpt from my book Math for Grownups.  (Check it out for more great ideas on using math in your everyday life.)  Happy Thanksgiving!

As any experienced cook will tell you, timing is often the most difficult skill to master in the kitchen. Nobody wants to sit down to a meal of overdone fish, cold broccoli, and room-temperature biscuits. (The butter should melt into the flaky layers, you know?)

Figuring out how long a dish should bake, roast, or boil is the first step to presenting a carefully choreographed dinner. And for many novice or not-so-frequent home chefs, a giant turkey is the most daunting of all entrées.

Sure, you can count on the pop-up timer. These come with some turkeys, or you can buy one separately. But you’ll still need to know when to put the bird in the oven—and when to start boiling the potatoes.

And there’s also the thawing time. Buying a frozen turkey means allowing time for it to defrost, which is probably a lot longer than you think!

But you don’t need Julia Child or a semester at Le Cordon Bleu to figure any of this out. Thawing times and cooking times depend on the turkey’s weight.

It’s your first Thanksgiving with your new husband, Tom. And your mother-in-law will arrive just in time for the 6:00 P.M. dinner. She’s bringing pecan pie, stuffing, and homemade rolls. You’re in charge of all the rest—including the turkey. You’ve ordered a 12-pound bird, which you’ll need to thaw in the fridge before roasting. When should you pull it out of the deep freeze?

You know from your sister’s horror stories that you can’t cut corners by thawing the bird on the counter. Unless you want to host the Thanksgiving-dinner-when-everyone-got-Salmonella, your best bet is to defrost the turkey in the refrigerator. The United States Department of Agriculture(USDA) says to allow 5 hours of thawing time per pound. They oughta know, right?

You’ve bought a 12-pound turkey. How long should you allow for thawing?

It’s a simple problem, really. Just multiply the number of pounds by 5—the number of hours needed to thaw each pound.

12 xŸ 5 = 60

So you need to put the turkey in the fridge for 60 hours in order to thaw it. But let’s think a moment. Does this mean 60 hours before dinner is served?  Nope. The USDA also says that serving raw poultry is a big no-no, so you’ll also need to roast the bird.

If your oven is set to 325ºF, the USDA recommends roasting an unstuffed turkey for 2¾ to 3 hours. They’re the experts on avoiding food-borne illnesses, so you decide to follow their recommendations.

With a little time for resting—the turkey, not you—and carving, you estimate that it will take 3 to 3¼ hours to get the bird from the fridge to the table. You’ll need to add that to the thawing time in order to figure out when to pull the turkey out of the freezer.

60 + 3¼ = 63¼ hours

Clearly you’ll need more than a day, but how much more?  There are 24 hours in a day. How many 24s are there in 63¼?  You can use a calculator, but that could be confusing. Instead, try some mental math.

To make things easier, forget about the extra ¼ hour (or 15 minutes). You can add that on to the end. Working with whole numbers is much easier.

It looks like you’ll need at least 2 days. That’s because 24 times 2 is 48, which is less than the total time you have figured out. Will you need a third day?  You can subtract to find out.

63 – 48 = 15

So 2 days and 15 hours (plus the extra 15 minutes) ought to do it. But that doesn’t tell you what time to start defrosting the turkey, does it?

Remember, your dinner starts at 6:00 P.M. Fifteen hours before that is 3:00 A.M., and another 15 minutes before that is 2:45 A.M. So you will have to take the turkey out of the freezer at 2:45 A.M. on the Tuesday before Thanksgiving.

Because you’re doing all the cooking, you decide to let Tom get up to move the turkey from the freezer to the fridge. You set his alarm on Monday night and settle in for the last good night’s sleep of the week.

Do you have any Thanksgiving cooking horrors to share?  Do tell (in the comments section)!

Read More
By
In Math at Work Monday

Math at Work Monday: Brette the cookbook author

I like to cook and bake (especially pies and bread), but the idea of developing a recipe that others can use makes my hands sweat.  To be honest, I don’t really understand the difference between baking soda and baking powder (except that soda interacts with vinegar in a really cool way), and figuring out how long to keep something in the oven — and at what temperature — is a mystery to me.

So when my friend and fellow writer, Brette Sember let me know that she has a cookbook coming out, I jumped at the chance to feature her here.  It should be no surprise that math is a critical ingredient of all recipes.  The Parchment Paper Cookbook is no exception.  Her recipes offer easy ways to cook healthy meals without pots or pans. You can get a taste of her recipes at her blog: No Pot Cooking.

What do you do for a living?

I write books, blogs, and articles, and I also do indexing, ghostwriting, and copyediting.  One of my specialties is recipe development and food writing.

When do you use basic math in your job?

I have one cookbook out, The Parchment Paper Cookbook, and The Muffin Tin Cookbook is on the way. I’m finding there is a lot more math involved in writing cookbooks than I expected! When I was just cooking for my family I did a lot of dumping of ingredients, but now that I have to record my recipes, I have to do a lot of measuring. And I also have to do a lot of conversions of measurements.

Test recipes are much smaller than the ones I publish in my cookbooks.  So, after testing a recipe, I have to convert the ingredient amounts for publication. This gets a little complicated when you’re dealing with teaspoons and tablespoons.  For example, if make a test recipe with 3 tablespoons of an ingredient and I want to quadruple that to make a full batch, I would multiply by 4 to get 12 tablespoons. But I have to express that as ¾ cup.

Do you use any technology to help with this math?

Yes definitely. I don’t trust myself to get it right, and it absolutely has got to be accurate.

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

I’m able to give readers the most convenient measurement possible for them.

How comfortable with math do you feel?

I have to admit I don’t feel very comfortable with math. This is kind of funny because from 7th to 11thgrade I was in a special gifted math program where I went to the local university for math with kids from other school districts in my county. We learned a creative approach to math. Regardless, I never felt comfortable with math. So, no, I guess I would say I don’t enjoy the math aspect, but it’s essential to what I’m doing so I am careful to do it right.

Did you like the math you took in high school?

I got great grades until I took a traditional calculus class with college students in 11th grade. I got a D! I dropped out of the program then. I didn’t have to take math in college, because I had earned so many credits through that program.

Did you have to learn new skills in order to do this math?

It is pretty basic, but I had to refresh my memory for some of the conversions.

Thanks, Brette, for appearing in today’s Math at Work Monday.  Readers, if you have questions for Brette, feel free to post them below.  I’ll be sure to let her know and ask her to come by for a quick response.  And if you’re looking for a great holiday gift for someone who is too busy to cook and clean up, check out The Parchment Paper Cookbook.  Or pick up a copy for yourself!

Read More
By