1.8 KiB
epic, story, title, status
| epic | story | title | status |
|---|---|---|---|
| 6 | 6.4 | Financial Functions | draft |
Epic 6 — Advanced Math & Functions
Goal: Scientific, financial, and power-user math.
Story 6.4: Financial Functions
As a CalcPad user, I want to use natural-language financial expressions for compound interest and mortgage calculations, So that I can quickly answer personal finance questions without looking up formulas.
Acceptance Criteria:
Given the user writes $5000 after 3 years at 7.5%
When the engine evaluates (compound interest, annual compounding by default)
Then the result is approximately $6,211.94
Given the user writes mortgage $350000 at 6.5% for 30 years
When the engine evaluates (standard monthly payment amortization)
Then the result is approximately $2,212.24 per month
Given the user writes $10000 after 5 years at 5% compounded monthly
When the engine evaluates
Then the result is approximately $12,833.59
Given the user writes mortgage $200000 at 4% for 15 years
When the engine evaluates
Then the result is approximately $1,479.38 per month
Given the user writes a compound interest expression with 0% interest When the engine evaluates Then the result equals the principal (no growth)
Given the user writes a mortgage expression with 0% interest When the engine evaluates Then the monthly payment is the principal divided by the total number of months
Given the user writes $5000 after 0 years at 7.5%
When the engine evaluates
Then the result is $5,000 (the principal unchanged)
Given the user writes a financial expression with missing or invalid parameters (e.g., mortgage at 5%)
When the engine evaluates
Then an error is displayed indicating the required format or missing parameters