Chelsea wants to buy a new iPhone that costs $324. She has already saved $56. If she can save $20 a week, how
many weeks will it take for her to be able to purchase the
iPhone?

14 full weeks.

Step-by-step explanation:

The phone costs $324 and she saved $56, so we subtract $56 from $324.

$324 - $56 = $268

She saves $20 each week so we divide $268 by $20 to get the number of weeks.

$268/20 = 13.4

It will take 13.4 weeks, but we have to round up because at 13 weeks she won't have enough saved. So 14 full weeks.