4.4+Buying+Beads+0910

2/12/09 SB **Big Idea**: Many important practical and mathematical applications involve comparing quantities of one kind or another; it is important to know which method to use and how we should use them. **Essential Question**: What methods are there for comparing things? **Notes from Class**: 1. 20/.12$ = 166 2/3 beads 2. Unit rates are comparisons in which denominators are one. Ex. 12 miles/ 1 gallons 3. Can you make unit rates in to fractions?


 * Problem 4.4: Write an equation relating the cost (c) and the number of beads (x) for each type of bead.**

Spheres: c= 0.6x

Cubes: c= 0.8x

Cylinders: c= 0.8x


 * Problem 4.4 Follow Up: For each type of bead, you could find two unit rates. You could find the number of beads for each unit of cost (in other words, for each cent), and you could find the cost for each bead.**


 * 1. Which unit rate would be most useful if you were trying to figure out the number of beads you could buy with a certain amount of money?**

To figure out how many beads you can buy with a certain amount of money, it would be more useful to use the unit rate that figures out the number of beads for each unit of cost.


 * 2. Which unit rate would be most useful if you were trying to figure out how much money a certain number of beads cost?**

To figure out how much money a certain number of beads cost, it would be more useful to use the unit rate that the cost for each bead is better.

Sphere: =Plot:=

Cubes: =Plot:=

Cylinders:

=Plot:=