Ahhh, tax time again. Millions of innocent Americans are filling in their 1040. Don't we all just love the IRS. If I were king, things would be a whole bunch simpler, with a simple computer program to compute tax. Here's how Geoff's IRS program would work:

Here what a sample run should look like (with the keyboard input shown in italics) ...
Enter next amount : 125000
Enter next amount : -250
Enter next amount : -3000
Enter next amount : 15000
Enter next amount : 88000
Enter next amount : -200
Enter next amount : 0

Income         = $228000.0
Deductions     = $3450.0
Taxable income = $224550.0
Tax group      = Q
Tax owed       = $56137.5 

Luckily, someone has already done the analysis and design, resulting in the following structure chart and algorithm ...

1. Input income and deduction
   1.1 Repeatedly until 0.0 is entered
       1.1.1 Prompt user
       1.1.2 Input value
       1.1.3 If positive 
           1.1.3.1 Add to income
       1.1.4 If negative 
           1.1.4.1 Add (absolute) to deduction
2. Compute taxable income
   2.1 If income >= deduction then taxable is income - deduction, else 
   2.2 Taxable is 0.0
3. Compute tax group
   3.1 If taxable >= 500000
       3.1.1 Group is S, else
   3.2 If taxable >= 200000
       3.2.1 Group is Q, else
   3.3 If taxable >= 100000
       3.3.1 Group is M, else
   3.4 If taxable >= 50000
       3.4.1 Group is A, else
   3.5 If taxable >= 20000
       3.5.1 Group is R, else
   3.6 Group is P
4. Compute tax
   4.1 Depending on the group
       4.1.1 For S and Q
           4.1.1.1 Tax is 25% of taxable
       4.1.2 For M
           4.1.2.1 Tax is 10% of taxable
       4.1.3 For A and R
           4.1.3.1 Tax is 3% of taxable
       4.1.4 For P
           4.1.4.1 Tax is 0.0
       4.1.5 For other groups
           4.1.5.1 Error!
5. Display tax information
   5.1 Display income
   5.2 Display deduction
   5.3 Display taxable
   5.4 Display group
   5.5 Display tax 

You must ...

Answer