Chapter 4, Problem 10PP

Fat Percentage Calculator

One gram of fat has 9 calories. If you know the number of fat grams in a particular food, you can use the following formula to calculate the number of calories that come from fat in that food:

$Caloriesfromfat=Fatgrams\times 9$

If you know the food’s total calories, you can use the following formula to calculate the percentage of calories from fat:

$Percentageofcaloriesfromfat=Caloriesfromfat÷Totalcalories$

Create an application that allows the user to enter:

• The total number of calories for a food item
• The number of fat grams in that food item

The application should calculate and display:

• The number of calories from fat
• The percentage of calories that come from fat

Also, the application’s form should have a CheckBox that the user can check if he or she wants to know whether the food is considered low fat. (If the calories from fat are less than 30% of the total calories of the food, the food is considered low fat.)

Use the following test data to determine if the application is calculating properly:

Note: Make sure the number of calories and fat grams are not less than 0. Also, the number of calories from fat cannot be greater than the total number of calories. If that happens, display an error message indicating that either the calories or fat grams were incorrectly entered.