Lab 04-1 Calculate the factorial of a number

In this exercise, youll create a form that accepts an integer from the user and then calculates the factorial of that integer. The factorial of an integer is that integer multiplied by every positive integer less than itself. A factorial number is identified by an exclamation point following the number. Heres how you calculate the factorial of the numbers 1 through 5: 1! = 1 which equals 1 2! = 2 * 1 which equals 2 3! = 3 * 2 * 1 which equals 6 4! = 4 * 3 * 2 * 1 which equals 24 5! = 5 * 4 * 3 * 2 * 1 which equals 120 To be able to store the large integer values for the factorial, this application cant use the Int32 data type.

1. Start a new project named Factorial. 2. Add labels, text boxes, and buttons to the default form and set the properties of the form and its controls so they appear as shown above. When the user presses the Enter key, the Click event of the Calculate button should fire. When the user presses the Esc key, the Click event of the Exit button should fire. 3. Create an event handler for the Click event of the Calculate button. This event handler should get the number the user enters, calculate the factorial of that number, display the factorial with commas but no decimal places, and move the focus to the Number text box. It should return an accurate value for integers from 1 to 20. (The factorial of the number 20 is shown in the form above.) 4. Create an event handler for the Click event of the Exit button that closes the form. 5. Test the application to be sure it works correctly.

Lab 04-2 Calculate change

In this exercise, youll develop a form that tells how many quarters, dimes, nickels, and pennies are needed to make change for any amount of change from 0 through 99 cents. One way to get the results is to use the division and modulus operators and to cast the result of each division to an integer. 6. Start a new project named ChangeCalculator. 7. Add labels, text boxes, and buttons to the default form and set the properties of the form and its controls so they appear as shown above. When the user presses the Enter key, the Click event of the Calculate button should fire. When the user presses the Esc key, the Click event of the Exit button should fire. 8. Create an event handler for the Click event of the Calculate button. Then, write the code for calculating and displaying the number of quarters, dimes, nickels, and pennies that are needed for the change amount the user enters. This code should provide for integer entries, but you can assume that the user will enter valid integer values. 9. Create an event handler for the Click event of the Exit button that closes the form. 10. Test the application to be sure it works correctly.

Lab 04-3 Calculate income tax

In this exercise, youll use nested if statements and arithmetic expressions to calculate the federal income tax that is owed for a taxable income amount entered by the user. This is the 2015 table for the federal income tax on individuals that you should use for calculating the tax: Taxable income Income tax Over But not over Of excess over $0 $9,225 $0 plus 10% $0 $9,225 $37,450 $922.50 plus 15% $9,225 $37,450 $90,750 $5,156.25 plus 25% $37,450 $90,750 $189,300 $18,481.25 plus 28% $90,750 $189,300 $411,500 $46,075.25 plus 33% $189,300 $411,500 $413,200 $119,401.25 plus 35% $411,500 $413,200 $119,996,25 plus 39.6% $413,200 11. Start a new project named TaxCalculator. 12. Add labels, text boxes, and buttons to the default form and set the properties of the form and its controls so they appear as shown above. When the user presses the Enter key, the Click event of the Calculate button should fire. When the user presses the Esc key, the Click event of the Exit button should fire. 13. Create an event handler for the Click event of the Exit button that closes the form. 14. Create an event handler for the Click event of the Calculate button. Then, write the code for calculating and displaying the tax owed for any amount within the first two brackets in the table above. This code should provide for decimal entries, but you can assume that the user will enter valid decimal values. To test this code, use income values of 8700 and 35350, which should display taxable amounts of 870 and 4841.25. 15. Add the code for the next tax bracket. Then, if you have the time, add the code for the remaining tax brackets (Do at least the first 3 tax brackets for credit).