Personal Apple π - A Delicious
Approach to Circle Geometry
Images & Recipe Adapted from www.freutcake.com
Using apple pies to teach is a sure-fire way to get students engaged! Try this simple
recipe and activity idea to demonstrate the basics of circle geometry… yes, we mean π.
Ingredients to make 10-12 pies, or π’s:
• 1 box store-bought pie crust (2 rolls), or your favourite recipe
• 2 cups washed, cored and diced Granny Smith apples (about
3 apples)
• 2 Tablespoons of all purpose flour
• 1 teaspoon of cinnamon & ¼ teaspoon of nutmeg
• ¼ cup sugar
• The juice of ½ a lemon (why? see activity 1!)
• Egg wash (1 egg whisked with 1 Tablespoon of water)
Method:
1. Preheat the oven to 425ºF and line a baking sheet with
parchment paper. Set aside.
2. In a bowl, combine the apples, lemon juice, cinnamon,
nutmeg, sugar and flour. Mix until apples are well coated.
3. Unroll the pie dough onto a clean, well-floured surface. Using a
circular cookie cutter, glass or jar, cut out as many circles as
you can. Using a rolling pin, roll out the scraps of your dough
and repeat the process, until you run out.
4. Spoon 1 Tablespoon of the apple filling into the centre of half
of the dough circles, remember to leave space around the
edge.
5. Brush around the edge of each circle with the egg wash (the
“glue”) and top with one of the remaining dough circles. Use a
fork to press around the edge, “crimping” the two pieces
together.
6. Brush each pie with the remaining egg wash and cut “vents”
into the top of each pie (you could make the π shape!)
7. Place each pie onto the lined baking sheet and refrigerate for
at least 30mins.
8. Bake at 425ºF for 15mins, or until golden brown. Enjoy!
w w w. f o o d s h a r e . n e t l t h e g r e a t b i g c r u n c h @ f o o d s h a r e . n e t l # g r e a t b i g c r u n c h
Inspired by: http://bedtimemath.org/apple-pi/
While your mini pies are in the fridge, oven and then cooling rack (roughly 50mins
total), try some of these geometry activities with your students!
circumference (C)
π = circumference (C)
area (A)
diameter (D)
diameter
(D)
and therefore,
π xD =C
radius (R)
Test the Theory!
1. Using a piece of yarn or string, measure the
circumference of your cookie cutter, glass or
jar and translate into centimeters,
millimeters or inches by lining up against a
ruler.
2. Now measure the diameter using a ruler.
Remember to use the same value as the
circumference (i.e. cm, mm, inches).
3. Substitute your values into the equation to
(hopefully) arrive at “pi” - roughly 3.14!
Question: If you had a ruler, but no string or
yarn, how could you find out what the
circumference of your cookie cutter is?
Question: Will the circumference of the cookie
cutter be the same as the pies that come out
of the oven? Why or why not? What about the
diameter? (Find out when your pies are ready!)
w w w. f o o d s h a r e . n e t l t h e g r e a t b i g c r u n c h @ f o o d s h a r e . n e t l # g r e a t b i g c r u n c h