Has been planning to do this for sometime, but here is a list of excel
sheet computations which I developed during my Investment Science course in Stanford, these may help you understand some investment
related calculations (like mortgages, Net Present Value, Internal rate
of return and so on), the one which may be of frequent use is the
mortgage/loan payment schedule given the interest rate and the number of
years, personally was of good use to me.

Note: Most of them may be in openoffice format, you may download openoffice software to use these.

1. Spreadsheet:Compound interest calculation

2. Spreadsheet:Calculating Net Present Value (NPV) and Internal rate of return (IRR)

Note: Most of them may be in openoffice format, you may download openoffice software to use these.

1. Spreadsheet:Compound interest calculation

2. Spreadsheet:Calculating Net Present Value (NPV) and Internal rate of return (IRR)

3. Spreadsheet:Reusable Spreadsheet for computing the amortization schedule of a mortgage/loan payment

4. Net Present Value vs Internal rate of return analysis in investment decisions - Spreadsheet:Problem 2.11 from Investment Science, Luenberger

5. Incremental internal rate of return for analyzing alternate investment options - Spreadsheet: Problem 2.8 from Investment Science, Luenberger

6. Bond Portfolio Immunization Example - Spreadsheet: Problem 3.12 from Investment Science, Luenberger