Math Food for Pi Approximation Day

July 22 is Pi Approximation Day because pi's fractional approximation is 22/7. To celebrate, here are some math foods Miss C rounded up last year.

Food is often used to illustrate shapes, and recipes are used to introduce children to measurement and proportions. But if you really care about your mathematics -and your food- there are ways to take the marriage of math and food to the next level!

Pi Pie

The simplest way to incorporate math into food is to bake a Pi Pie. Meg made this lovely Pi Pie to celebrate Pi Day in 2004. It's a normal fruit pie with the pi symbol carved into the top crust. Then the numerals of pi were cut from pie crust and added to the rim of the pie. Yummy!

Möbius Strip Bagel

George Hart, who I've run across before, has turned breakfast into a puzzle with a bagel that has been sliced into two halves that are linked together! The secret is that the cut itself is a two-twist Möbius strip. If you can't quite visualize that, there are explicit instructions for this project. This is sure to impress your mother-in-law, one way or another.

Sierpinski Carpet Cookies

Sierpinski Cookies-11

Lenore at Evil Mad Scientist Laboratories made cookies in the fractal pattern of the Sierpinski Carpet. These are made with butter cookie dough, a portion of which was colored with delicious cocoa powder. The dough is shaped, stacked, and stretched, then stacked and stretched again, and when the fractal is at your limit, the dough is sliced to make cookies. Illustrated instructions are included at the laboratory link.

Fractal Snowflake Cupcakes - 24

Lenore also gave us instructions for making this beautiful fractal cupcake in the Koch Snowflake pattern. This uses the same method of stacking and rolling out iterations of fondant, this time tinted blue or left white.

Menger Sponge Gingerbread House

This fractal gingerbread house resembles the Sierpinski carpet a bit, but a Menger sponge contains holes rather than cocoa cookie dough.

A Menger sponge is a 3D fractal that starts with a cube. In each iteration the surface of each cube is divided into 9 sections and the middle section is pushed out.

In the next iteration, you look at the smaller subcubes of the original cube and repeat the same process.

in the picture below you can see the same process. With this gingerbread fractal we'll be making a level 2 Menger sponge and using decoration to make it look like a level 3.

The actual making of the gingerbread is easier than the explanation of the fractal. Understanding fractals can be plenty intuitive when you've seen them built.

Sierpinski Hamantaschen

Hamantaschen is a Jewish holiday pastry that comes in a triangle shape filled with prunes, poppy seeds, or other sweet filling. Deborah Gardner took her family's traditional recipe and made "Sierpinskitaschen," or Sierpinski Hamantaschen. This is not pieced together like the cookies, but it begins with a large pastry which is then subdivided as may times as you can.

Apple Chain

Marius van Voorden enjoys food sculpting. He was inspired by Neil Fraser's soap carvings of links from a single solid, and decided to do the same with apples. You won't find step-by-step instructions, but I suppose it's about as difficult as cutting the bagel above.

Hyperbolic Dried Fruit

Vi Hart has a gift for making mathematics into something enjoyable, even if you can't keep up with the math. She wrote on The Hyperbolic Nature of Dried Fruit Slices because she found it strange that when sliced fruit dried, it not only shrunk but changed shape completely, in a predictable manner. For example, as it dries, an apple slice curls up into a hyperbolic plane! Hart did some experiments and found that it made no difference whether she cut the apple vertically or horizontally, or whether the peel was removed. The same effect can be seen in potato chips, which are fried instead of dried. See Hart's other posts on slicing apples into mathematical shapes.

Cutting the Cheese

High school senior Luyi does many things with geometric shapes. Recently she cut the cheese into a multitude of shapes. A solid cube of cheese became a hexagonal prism, then with some intricate-but-understandable steps, Luyi was left with "one funky-shaped polyhedron and six small congruent tetrahedra." Then the fun starts, as you can find the volume of your irregular polygon by calculating the volume of the shapes you cut off! Or, you could just get the crackers out and finish off this experiment.

Also check out Luyi's Dark and white chocolate Sierpinski triangle brownies. Now every time I come across a Sierpinski triangle, I will start to feel hungry.

The Secret World War II History Hidden in London's Fences

In South London, the remains of the UK’s World War II history are visible in an unlikely place—one that you might pass by regularly and never take a second look at. In a significant number of housing estates, the fences around the perimeter are actually upcycled medical stretchers from the war, as the design podcast 99% Invisible reports.

During the Blitz of 1940 and 1941, the UK’s Air Raid Precautions department worked to protect civilians from the bombings. The organization built 60,000 steel stretchers to carry injured people during attacks. The metal structures were designed to be easy to disinfect in case of a gas attack, but that design ended up making them perfect for reuse after the war.

Many London housing developments at the time had to remove their fences so that the metal could be used in the war effort, and once the war was over, they were looking to replace them. The London County Council came up with a solution that would benefit everyone: They repurposed the excess stretchers that the city no longer needed into residential railings.

You can tell a stretcher railing from a regular fence because of the curves in the poles at the top and bottom of the fence. They’re hand-holds, designed to make it easier to carry it.

Unfortunately, decades of being exposed to the elements have left some of these historic artifacts in poor shape, and some housing estates have removed them due to high levels of degradation. The Stretcher Railing Society is currently working to preserve these heritage pieces of London infrastructure.

As of right now, though, there are plenty of stretchers you can still find on the streets. If you're in the London area, this handy Google map shows where you can find the historic fencing.

[h/t 99% Invisible]

Custom-Design the Ugly Christmas Sweater of Your Dreams (or Nightmares)

For those of you aspiring to be the worst dressed person at your family's holiday dinner, sells—you guessed it—ugly Christmas sweaters to seasonal revelers possessing a sense of irony. But the Michigan-based online retailer has elevated kitsch to new heights by offering a create-your-own-sweater tool on its website.

Simply visit the site's homepage, and click on the Sweater Customizer link. There, you'll be provided with a basic sweater template, which you can decorate with festive snowflakes, reindeer, and other designs in five different colors. If you're feeling really creative, you can even upload photos, logos, hand-drawn pictures, and/or text. After you approve and purchase a mock-up of the final design, you can purchase the final result (prices start at under $70). But you'd better act quickly: due to high demand, orders will take about two weeks plus shipping time to arrive.


More from mental floss studios