CPM Homework Help : CC1 Problem 9-78

Jenna was building a fence for her new sheep’s pen. She needs a total of $40$ linear feet of lumber. Some of her neighbors have agreed to give her lumber, and she wants to know if she has enough.

Neighbor Jim will give her a board that he says is $8\frac { 1 } { 2 }$ feet long. Neighbor Malia will give her two boards that she says are each $126$ inches long. What is the total combined length of lumber Jenna has received?
Hint (a):
The best way to determine the length Jenna has is to put all the board lengths into the same units. Using feet will make it easier to determine if Jenna has enough at the end. Jim has $8.5$ feet to give. Malia has $2\left(126\right)$ inches. How many feet is $2\left(126\right)$ inches?
More Help (a):
Can you do this calculation in your head? There are $12$ inches in $1$ foot, therefore $12$ 0 inches is $10$ feet.

Neighbor Mike called and offered to donate a board that is $400$ centimeters long. Jenna found the conversion information at right. Help her decide if she has enough lumber to make her pen.
Hint (b):
$100 \text{ cm} = 1 \text{ m}$
Therefore, $400$ centimeters is equal to $4$ meters.
How many feet is $4$ meters?

$\left. \begin{array} { c } { 1 \; \text{cm} = 0.3937 \; \text{in.} } \\ { 1 \; \text{m} = 3.281 \; \text{ft} } \\ { 100 \; \text{cm} = 1 \; \text{m} } \end{array} \right.$