Documentation

User Manual

Everything you need to know to use the CalcOS TI-84 calculator.

🚀 Getting Started

Opening the Calculator
Navigate to the Calculator page or click "Launch Calculator" in the navigation. The calculator loads instantly — no login or download required.
Basic Input
Type numbers and operators using your keyboard, or click the on-screen keys. The expression appears in the LCD display as you type.
Evaluating Expressions
Press the ENTER key (on-screen or keyboard) to evaluate your expression. The result appears on the display.
Clearing Input
Press CLEAR to clear the current expression. Press CLEAR again on an empty expression to clear the history.

🔢 Basic Operations

+, -, ×, ÷
Standard arithmetic operators. Use the orange column keys on the right or keyboard +, -, *, / keys.
Parentheses
Use ( and ) keys for grouping. CalcOS follows standard order of operations (PEMDAS).
Negative Numbers
Use the (-) key (not the minus key) for negative numbers. Example: (-5) × 3
Decimals
Press the decimal point key. Example: 3.14 × 2

📐 Advanced Functions

sin, cos, tan
Trigonometric functions. Make sure to set DEG or RAD mode first using the MODE key.
sin⁻¹, cos⁻¹, tan⁻¹
Inverse trig functions. Press 2nd first, then sin/cos/tan.
√(
Square root. Press 2nd + x² to get √(. Close the parenthesis after your expression.
x²
Squares a number. Press x² after entering a number.
log, ln
Log base 10 and natural logarithm.
^
Exponent. Example: 2^10 = 1024.
π
Pi constant (~3.14159). Press 2nd + ^.

⌨️ Keyboard Shortcuts

Enter
Evaluate expression
Backspace
Delete last character
Escape / Delete
Clear expression
Arrow Left/Right
Move cursor
Arrow Up/Down
Browse history
0-9, +, -, *, /, ^, (, ), .
Direct input

💾 Memory & History

Calculation History
Previous calculations appear in the LCD display. Use the up arrow to navigate back through history.
ANS variable
The result of the last calculation is stored in ANS. Press 2nd + (-) to insert ANS into your expression.
STO
Store the current answer to memory. Press 2nd + STO (RCL) to recall it.

⚙️ Settings

Degree/Radian Mode
Press MODE to toggle between degree and radian mode. DEG/RAD shown in the status bar.
Vibration
Toggle vibration feedback (mobile devices).
Sound
Toggle key click sounds.
LCD Contrast
Adjust the display brightness using the contrast slider.
Open Calculator Now Key Reference →