The value of a telephone calling card decreases 20cents for each minute used. Write an integer to express the change in the cards value for a 4 minute call. Use a negative number to represent the card losing value.
- $0.80
To find the change in the calling card's value for a 4-minute call, we need to calculate the decrease in value per minute and then multiply it by the number of minutes used.
The given information states that the card's value decreases by 20 cents for each minute used. Since the value is decreasing, we need to use a negative number to represent this decrease.
So, to find the change in the card's value for a 4-minute call, we can write it as:
Change in value = decrease in value per minute × number of minutes used
Change in value = -20 cents/minute × 4 minutes
Change in value = -80 cents
Therefore, the change in the card's value for a 4-minute call is -80 cents.