Pose the following problem to students:
On Planet Gzorp, the children eat pieces of candy called Zonks and Zorks. Zonks and Zorks come in the same size bag. A whole bag of Zonks weighs the same as a whole bag of Zorks. If there are 50 pieces in a whole bag of Zonks, and 25 pieces in a whole bag of Zorks, which is larger, a Zonk or a Zork? How do you know?
After presenting the problem, ask:
- What information from this problem is important to know in order to find a solution? (Possible response: You need to know that the two kinds of candy come in the same size bag and that the two bags weigh the same. You need to know that there are 50 Zonks in a bag and 25 Zorks in a bag.)
- Which is larger, a Zonk or a Zork? How do you know? (A Zork is larger. Possible response: There are twice as many Zonks in a bag, so they are smaller because more can fit in a bag.)
- How can you use fractions to write a number sentence showing the relationship between Zonks and Zorks? (Possible response: You need 2 Zonks for every one Zork. There are 50 Zonks in a whole bag and 25 Zorks in a whole bag. That means the unit whole for Zonks is divided into 50 pieces and the unit whole for Zorks is divided into 25 pieces. Since the unit wholes are the same sizes, 2/50 = 1/25.)
