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Robert Foote Disney Magnet School
4140 N. Marine Drive
Chicago IL 60613
Students will draw a circle using string and a ruler.
Students will determine areas of different size circles.
Students will determine area of a sector of a circle.
Students will find how many two topping pizzas can be made using 14 toppings.
Students will determine cost per square inch.
*cardboard or posterboard *paper plate
*pizza menus *6 inch circle
Ask what the shape of a pizza is. Hold up the six inch circle and explain that
this circle is the size of a six inch personal pan pizza. Then hold up the
paper plate and tell them it is nine and one half inches. Then pass out pizza
menus and ask students for the sizes of pizzas indicated on the menus. After
students name the different pizza sizes, ask them how these sizes are
determined. They should recognize that these are the diameters of the pizza.
Next, have each student using the cardboard, string, and a ruler draw a circle
the size of the pizza diameters. Have them draw over the circles in marker.
Bring each of the pizzas up to the board and display them. Next, find the area
of each size pizza. Compare the prices to the areas and determine the price per
square inch. Have students determine which size is the best buy. Next ask
students how they would find the area of a slice of a pizza. Cut a piece out of
the paper plate and measure the angle of the sector and then using the angle
find the area of the slice of pizza. For example, 60 degrees would be one-sixth
of the area of the circle. Finally, give the students the menus again and have
them enumerate all the pizza toppings mentioned in the flyer. Then have them
find all the two topping pizzas they can make using those toppings.
As a performance assessment for this lesson, you could cut out several different
slices of pizza and have students find the area. You could give them another
menu and determine the difference in price and you could also have them
construct circles of different sizes.