Basic Calculator
A clean, full-featured basic calculator with memory functions and calculation history.
A full-featured everyday calculator for addition, subtraction, multiplication, division, square roots, and percentages, with memory storage and a running calculation history.
How Basic Calculator Works
As you tap digits and operators, the calculator builds an expression string, and pressing "=" evaluates that full expression at once rather than calculating left to right one step at a time. Because of this, it follows standard order of operations — multiplication and division are applied before addition and subtraction, just like on paper.
The memory keys (M+, M−, MR, MC) store a separate running total independent of whatever is on the main display, so you can add to or subtract from that stored value while continuing unrelated calculations, then recall it later with MR.
The % key converts the number currently on screen directly to its hundredth (dividing by 100), and √ takes the square root of the displayed value. Every completed calculation is added to a scrollable history list showing the last ten results.
See It In Action
Who Uses Basic Calculator and Why
- Running everyday arithmetic — totaling a receipt, splitting a bill, or computing a tip percentage.
- Holding a running subtotal in memory (M+) while doing an unrelated calculation on the main display, then recalling it (MR) afterward.
- Taking a quick square root for a simple geometry or measurement problem.
- Reviewing the last ten calculations in the history list to double-check a multi-step arithmetic sequence.
Mistakes to Avoid
- Expecting left-to-right evaluation instead of standard order of operations — 12 + 7 × 3 evaluates the multiplication first (21) then adds 12, giving 33, not 57.
- Assuming the % key computes "a percentage of another number" — it actually just divides whatever's currently on the display by 100 directly (250 → 2.5).
- Confusing MC (clear memory) with clearing the display — MC only resets the separately stored memory value, not whatever is currently shown on screen.
Tips for Best Results
- Use M+ and M− to hold a running subtotal while you work through unrelated calculations, then press MR whenever you need to bring it back.
- Use your keyboard's number keys, +, −, *, /, and Enter for faster entry instead of clicking each button.
Fixing Common Problems
Pressing % didn't give the percentage-of-a-number result I expected. — The % key here divides the displayed value by 100 directly rather than computing "X% of Y" — compute the base percentage first, then multiply by the other number separately if needed.
MR is recalling a value I don't recognize. — Memory is a separate running total from the main display — check whether you pressed M+ or M− earlier in the session without noticing, and press MC to reset it.
Terms Explained
Order of operations: The standard convention (often abbreviated PEMDAS) that evaluates multiplication and division before addition and subtraction within an expression.
Memory keys: M+, M−, MR, and MC, which store, adjust, recall, and clear a separate running total independent of the main display.