Basic
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Basic Calculator

A fast, no-friction calculator for everyday math — addition, subtraction, multiplication, division, percentages, and sign-flip — with a clear running history above the result and a 14-digit display.

How to use it
  • Tap or click digits to enter a number, then press an operator (+, −, ×, ÷) and the next number.
  • Press = or Enter to compute. The result becomes the next operand if you keep going.
  • The history line above the display shows the expression being built so you can double-check your input.
  • Press Clear once to clear the current entry. Press it again (or Escape) for an all-clear that resets the calculation.
  • +/− flips the sign of the displayed value. Useful when you've entered a number and want it to be negative.
  • % divides the displayed value by 100. Combined with an operator it computes a percentage of the previous value — for example, 200 + 10% gives 220.
Keyboard shortcuts
  • 0–9 and . — digits and decimal point
  • +, -, *, / — operators
  • Enter or = — evaluate
  • Backspace — delete the last digit
  • C — clear; Escape twice — all-clear
  • % — percent
  • _ — flip sign (the +/− key)
  • B, S, G, F — switch to Basic, Scientific, Graphing, or Financial
Worked examples
  • Sales tax — total of $42.95 at 8.75% tax: 42.95 × 1.0875 = 46.71
  • Tip — 18% tip on a $56.40 meal: 56.40 × 0.18 = 10.15
  • Percent off — $89.99 with 25% off: 89.99 × 0.75 = 67.49
  • Compound growth — $1,000 at 5% per year for 3 years: 1000 × 1.05 × 1.05 × 1.05 = 1157.63
  • Splitting a bill — $124.50 split four ways: 124.50 ÷ 4 = 31.125
RPN mode

The RPN toggle in the top-right corner switches the calculator into Reverse Polish Notation — a stack-based entry style popular with engineers and HP-calculator users. Instead of 2 + 3 =, you enter 2, push it onto the stack with Enter, then 3 + to compute. Each operation consumes operands from the top of the stack and pushes the result back. RPN avoids parentheses entirely once you get used to it.

Tips and limits
  • Results are shown to up to 14 significant digits. Beyond that, very large or very small numbers switch to scientific notation.
  • Dividing by zero returns Error; press Clear to recover.
  • Need trigonometry, logs, or powers? Switch to Scientific mode.
  • Need to plot a function? Use the Graphing calculator.