Bridge to College Mathematics Student Workbook
L4 Task #13: Swimming Pool
Del Carmen
Unit 8
You want to build a square swimming pool in your backyard. Let s denote the length of each side of the
swimming pool (measured in feet). You plan to surround the pool by square border tiles, each of which is one
foot by one foot (see figure).
5
18
Border tile
A teacher asks her students to find an expression for the number of tiles needed to surround such a square
pool, and sees the following responses from her students:
$\bullet$ 4(s + 1)
$\bullet$ $s^2$
$\bullet$ 4s + 4
$\bullet$ 2s + 2(s + 2)
$\bullet$ 4s
Is each mathematical model correct or incorrect? How do you know?
Response
4(s + 1)
$s^2$
4s + 4
2s + 2(s + 2)
4s
Is the statement correct or incorrect? How do you know?
