Pre-Algebra Tuesday September 2

Learning Target I will be able to determine whether two ratios are equivalent or find which of the ratios is more favorable.

What did we do last time? In Investigation 1 how did we compare the juice mixes? How did we scale up a ratio? How did we scale down a ratio?

Launch Video http://mathdashboard.com/cmp3 In this investigation we will decide which table will get more pizza by looking at equivalent ratios

Problem 2.1 A The campers at each table share the pizzas equally. Does a person sitting at a small table get the same amount of pizza as a person sitting at a large table? Can we use a similar strategy to compare the amount of pizza?

Problem 2.1 B Selena wonders whether a person at a small table or a person at a large table gets more pizza. She uses two ratios 8:3 and 10:4 and says : “The difference of 10 and 4 is 6. The difference of 8 and 3 is 5. The large table has more people so the people at the small table will get more pizza.” Can we use a similar strategy to compare the amount of pizza?

Problem 2.1 B Selena wonders whether a person at a small table or a person at a large table gets more pizza. She uses two ratios 8:3 and 10:4 and says : “The difference of 10 and 4 is 6. The difference of 8 and 3 is 5. The large table has more people so the people at the small table will get more pizza.” Can we use a similar strategy to compare the amount of pizza? Do you agree with Selena’s reasoning? Explain.

Problem 2.1 B Do you agree with Tony’s reasoning? Explain. Tony disagrees with Selena he says : “If you place five pizzas on the large table and three pizzas on the small table, Selena’s method would show that the campers at the large table and the campers at the small table get the same amount of pizza. If ten people share five pizzas, however, each person gets ½ a pizza. That’s more pizza than each of the eight people who share three pizzas will get.” Can we use a similar strategy to compare the amount of pizza? Do you agree with Tony’s reasoning? Explain.

Problem 2.1 C There are 160 campers. If everyone sits at small tables, how many pizzas should the camp director order (there are 3 pizzas on the small tables). If everyone sits at large tables, how many pizzas should the camp director order (there are 4 pizzas on the large tables)? Can we use a similar strategy to compare the amount of pizza?

Problem 2.1 C There are 160 campers. The camp director also has extra-large tables that seat 25. How many pizzas should be placed at these tables? Which ratio should you use to scale up to a table that seats 25? The ratio of 3:8 or the ratio of 4:10? Can we use a similar strategy to compare the amount of pizza?

Rate your learning I will be able to determine whether two ratios are equivalent or find which of the ratios is more favorable.