Financial Calculator User Guide
SI · Simple interest
Choose an instruction to see the matching keys and values. Practice separately in the real calculator.
Open financial calculator ↗Worked examples
Know the mode controls
Store Dys, I% and PV, then select SI or SFV and SOLVE. Use a negative PV for money paid out. Settings chooses a 360- or 365-day interest year.
Review these controls before choosing a case. Keystroke steps show menus opening, selection and closure.
SI · Open lesson
SI · Simple Interest — Interest for Dys days using the selected annual day basis. Its sign is opposite to PV when the interest rate is positive.
1. Organize the inputs
Simple interest for 120 days
Invest 10,000 (PV=-10000) at 5% simple annual interest for 120 days using a 365-day basis. Find SI.
| Variable | Input | Action |
|---|---|---|
| Dys | 120 | EXE |
| I% | 5 | EXE |
| PV | -10,000 | EXE |
| SI | Unknown | Select → SOLVE |
2. Follow the keystrokes
Steps 1–6
Steps 7–10
3. Show answer and interpretation
amount
Interest is principal × annual rate × days ÷365. SI is positive interest received; SFV includes returned principal.
4. Avoid these mistakes
- Simple interest does not compound. The 360/365 basis changes the answer; days are not years.
- Finish input with EXE before solving. Clear or changed inputs/settings invalidate earlier results; calculate again.
5. Practice it yourself
The link opens a separate calculator tab. It does not fill, clear or change your calculator's inputs; follow the settings and rows above.
Practice in the financial calculator (new tab) ↗SFV · Open lesson
SFV · Simple Future Value — The signed future receipt including principal and simple interest, using the same currency as PV.
1. Organize the inputs
Simple Future Value — manual workflow
Invest 10,000 for 120 days at 5% simple annual interest. Given Dys=120 · I%=5 · PV=-10000, use the settings below to find SFV manually.
| Variable | Input | Action |
|---|---|---|
| Dys | 120 | EXE |
| I% | 5 | EXE |
| PV | -10,000 | EXE |
| SFV | Unknown | Select → SOLVE |
2. Follow the keystrokes
Steps 1–6
Steps 7–10
3. Show answer and interpretation
amount
Simple Future Value: 10164.383561643835. The signed future receipt including principal and simple interest, using the same currency as PV.
4. Avoid these mistakes
- Simple interest does not compound. The 360/365 basis changes the answer; days are not years.
- Finish input with EXE before solving. Clear or changed inputs/settings invalidate earlier results; calculate again.
5. Practice it yourself
The link opens a separate calculator tab. It does not fill, clear or change your calculator's inputs; follow the settings and rows above.
Practice in the financial calculator (new tab) ↗SFV · 360 · Open lesson
SFV · 360 · Simple Future Value · 360-day basis — The signed future receipt including principal and simple interest, using the same currency as PV.
1. Organize the inputs
Simple Future Value · 360-day basis — manual workflow
Invest 10,000 for 120 days at 5% simple annual interest. Given Dys=120 · I%=5 · PV=-10000, use the settings below to find SFV manually.
| Variable | Input | Action |
|---|---|---|
| Dys | 120 | EXE |
| I% | 5 | EXE |
| PV | -10,000 | EXE |
| SFV | Unknown | Select → SOLVE |
2. Follow the keystrokes
Steps 1–6
Steps 7–10
3. Show answer and interpretation
amount
Simple Future Value · 360-day basis: 10166.666666666666. The signed future receipt including principal and simple interest, using the same currency as PV.
4. Avoid these mistakes
- Simple interest does not compound. The 360/365 basis changes the answer; days are not years.
- Finish input with EXE before solving. Clear or changed inputs/settings invalidate earlier results; calculate again.
5. Practice it yourself
The link opens a separate calculator tab. It does not fill, clear or change your calculator's inputs; follow the settings and rows above.
Practice in the financial calculator (new tab) ↗Supported results and operating manual
Targets across the lessons: SI · SFV
SI · Operating manual
- Enter interest days Dys, annual simple rate I% and PV; an invested principal can be negative.
- Select 360/365 day basis in Settings.
- Solve SI for interest or SFV for principal plus interest.
Keys and settings
Keys and workflow
- ↑↓ selects the active row. The highlighted row is the variable you are editing.
- Enter a number or expression (500*6 or 10000*(1.05)^10), then EXE to evaluate, store and advance. Dates use date input instead of expressions.
- SOLVE calculates the selected unknown/output from the other known values. MATH uses EXE only.
- CLR clears the draft while editing; otherwise it clears only the selected stored variable. Backspace recalls a stored value and deletes its last character, then EXE stores the change. Escape cancels a draft and restores the original value. After EXE advances, select the field you want to change. Clearing a stored input invalidates dependent results. Selecting a read-only result or history row leaves it untouched; settings and MATH history are preserved. MENU offers current-mode clear and calculator reset.
MENU → Fill Example provides working inputs for the current mode. N/A or an error means the inputs/settings do not support a valid result; check the highlighted field and domain restrictions.
Need help with signs or EXE/SOLVE? Read FAQ