you're reading...

A Question, A Problem, and a Recipe for Pi Day 2017

Pi-Day-ImagePi Day is Tuesday, March 14, 2017 or 03.14.2017. Whether you are a serious math geek, a dabbler in numbers, or just a wanna-be, you’ll love Pi Day. Here in the U.S., we’ve been observing Pi Day for almost 30 years. The first Pi Day event occurred in 1988 and was hosted at the Exploratorium Museum and Learning Center in San Francisco, CA.

The concept of the number Pi or π or 3.1415… has been around for about 4,000 years. It is used in math to calculate a number of geometrical equations including the area of a circle, A = πr2, and the circumference of a circle, C = 2πr.

Here at A Bridge for Business & STEM, we recognize the importance of this mathematical constant, Pi. In honor of Pi Day 2017, we are providing a question, a math (calculus) problem, and a recipe.

Question: How many decimals of Pi do we really need?

This question was posed to the director and chief engineer for NASA’s Dawn Mission manager, Marc Rayman. Here’s what he said (short answer):

“To start, let me answer your question directly. For the Jet Propulsion Laboratory’s (JPL) highest accuracy calculations, which are for interplanetary navigation, we use 3.141592653589793.”

He goes on to explain in five more paragraphs why they don’t use more numbers since this is an endless constant, however, let’s stick with the simple answer above.

Calculus Problem: The centripetal acceleration of a particle moving in a circle is a = v2/r, where v is the velocity and r is the radius of the circle.

  1. Approximate the maximum percentage error in measuring the acceleration due to errors of 2 percent in v and 1 percent in r.
  2. Why is there an error in the radius r? (This question was asked by one of my students a few years ago.)

Apple Pie Pancakes With Maple Walnuts Recipe: (This recipe is courtesy of Delish.com and perhaps the best “pie” of all.)

apple-pie-pancakes-with-walnutsCooked to a delicate tenderness, diced apple pieces compliment toasted maple walnuts for the finishing touch on pancakes packed with spice.

Level: Easy   Yield: 12 4-inch pancakes   Serves: 4


  • 1½ c. all-purpose flour
  • ¼ c. granulated sugar
  • 1 tsp. baking powder
  • ½ tsp. baking soda
  • 1 tsp. apple pie spice
  • ½  tsp. kosher salt
  • 1/8 tsp. kosher salt
  • 2 large eggs
  • 1½ c. buttermilk
  • 1 apple
  • ½ c. maple syrup
  • ½ c. heavy cream
  • ½ c. roughly chopped toasted walnuts


  1. In a large measuring cup or bowl, whisk together the flour, sugar, baking powder, baking soda, apple pie spice, and 1/2 teaspoon salt.
  2. In a separate bowl, whisk together the eggs and buttermilk. Add the buttermilk mixture to the flour mixture and whisk until fully incorporated (a few small lumps are fine). Stir in the apple.
  3. Heat a large nonstick skillet over medium-low heat. Check the heat by sprinkling the skillet with water — when the water bubbles and evaporates immediately, pour 3 scant 1/4 cups of batter into the skillet.
  4. Cook the pancakes until bubbles begin to appear around the edges and in the center, about 1 to 2 minutes. Using a spatula, peek under the pancakes to check if they are golden brown, then carefully flip them.
  5. Cook the pancakes 1 minute more, peeking to make sure the underside is golden brown. Transfer them to a baking sheet and cover loosely with foil to keep warm. Repeat with remaining batter (if your pancakes stick, wipe the skillet with 1 teaspoon canola oil before cooking the next batch).
  6. Simmer the maple syrup and the remaining 1/8 teaspoon salt in a small saucepan over medium heat until slightly thickened, about 5 minutes. Stir in the heavy cream until fully incorporated; simmer for 1 minute. Stir in the walnuts and serve with the pancakes.

About Vi Brown

Vi is principal and CEO of Prophecy Consulting Group, LLC, an Arizona firm that provides business and engineering services to private and public clients. Prior to establishing her consulting practice in 2001, Vi worked with Motorola, Maricopa County Government, Pacific Gas & Electric, CH2M Hill, and Procter & Gamble. As an adjunct faculty member, Vi teaches undergraduate calculus classes and graduate level environmental courses. She is also a professional speaker.


No comments yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: