CPM Homework Help : CC3 Problem 1-58

Mr. Wright was making a table to figure out how much it costs to send a certain number of regular letters through the mail. Use proportional reasoning to complete his table at right.

Step 1:

First set up the proportion.

$\frac{2 }{0.9 } = \frac{n}{6.75}$

Step 2:

What did you multiply $0.90$ by to get $6.75$ ?

$7.5$

Step 3:

Multiply $2$ by $7.5$ to get the number of letters. Repeat this strategy for all of the blanks within the table.

Answer:

$15$ letters for $\$6.75$

Number of Letters	Cost of Stamps ($)
$10$	$4.50$
$2$	$0.90$
	$6.75$
$7$
$1$
$500$
	$18.90$