Cynthia Lanius

Who Wants Pizza? - Part 5

The last time that Ms. Martinez ordered pizza, there was 2/3 of a pizza left. Bobby came in and ate 1/2 of what was left. The other children were mad that Bobby ate 1/2 of it. Bobby said, "I only ate 2 pieces."

Was he right?

If there were12 pieces in a whole pizza, how many pieces did he eat? What fraction of a whole pizza did he eat?

Let's Explore

 
Here are the 12 original pieces of the pizza.

           
           

 


 
The children left 2/3 of it.

           
           

 
12

1
x 2

3
= 8


Bobby ate 1/2 of the 8 pieces left.

           
           

8

1
x 1

2
= 4


So Bobby ate 4 pieces of pizza.

On the next page we will investigate the fraction of the pizza that Bobby ate.

Something for You to Do

Directions:Use colored markers and the square grid paper to draw the fractions as we have above and multiply the following.

1. 1/4 x 2/3 of 12 pieces

(a. 2) (b. 1) (c. 12) (d. 8) (e. 4)


2. 4/5 x 1/4 of 20 pieces

(a. 2) (b. 1) (c. 12) (d. 8) (e. 4)


 
3. 2/3 x 3/4 of 24 pieces

(a. 2) (b. 1) (c. 12) (d. 8) (e. 4)


4. 4/5 x 1/2 of 20 pieces

(a. 2) (b. 1) (c. 12) (d. 8) (e. 4)


5. 1/2 x 1/2 of 4 pieces

(a. 2) (b. 1) (c. 12) (d. 8) (e. 4)


 
How Did You Do? Click on "Get Score" below.

Score =

Correct answers:


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lanius@math.rice.edu