# 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?

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 $5.2$c for every minute.

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

$10 = 1,000c $1 , 000 - 5.2 - 5.2 - 5.2 \text{ } \ldots \ldots . - 5.2 = 0$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: $5.2 c e n t s = 1$minute :.$10=1000 cents

$\therefore 1000 = \frac{1000}{5.2} = 192.3076923$ minutes

$\therefore = 192$ minutes (to the nearest minute))