A pre-paid calling card costs $10. If purchased, it will allow the user to make calls for 5.2 cents per minute until the $10 amount is used. How do you calculate the number of minutes, rounded to the nearest minute, of this calling card?

2 Answers
Mar 22, 2017

1000 div 5.2 = 192.3

You have 192 minutes on this call card.

Explanation:

In word problems like these, the first decision is which operation to do? " "+ - xx div?

You could think of this as a subtraction of 5.2c for every minute.

Keep subtracting 5.2c until you get to 0. The number of subtractions is the number of minutes you can use.

$10 = 1,000c

1,000 -5.2-5.2-5.2" " ....... -5.2 = 0

However, division is the short cut for repeated division.

1000 div 5.2 = 192.3

You have 192 minutes on this call card.

Mar 22, 2017

192 minutes (to the nearest minute)

Explanation:

5.2cents=1 minute

:.$10=1000 cents

:.1000=1000/5.2=192.3076923 minutes

:.=192 minutes (to the nearest minute))