Basic Calculator
Add, subtract, multiply, and divide with memory (MC, MR, M+, M−), calculation history, percentage, and square root. Click the buttons or type on your keyboard.
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How It Works
Enter a number, press an operator, enter the next number, press =. The expression bar above the display shows the full expression as you type. Chain multiple operations: 100+50−30×2= processes left to right: 100+50=150, 150−30=120, 120×2=240. For PEMDAS order, use the Scientific Calculator.
Chain: evaluates left to right in entry order100 + 50 − 30 × 2 = 240 (chain: left to right)Compute your first value → M+. Compute the next → M+. Continue until done, then press MR for the total. M− subtracts from memory instead. MC resets memory to zero. The memory value persists across calculations until you clear it. Memory is shown in the corner when active.
M+ adds | M− subtracts | MR recalls | MC clearsShopping: 12.50 M+, 8.99 M+, 3.75 M+ → MR shows 25.24The % button computes a percentage relative to the previous operand. For a 15% tip on $48: press 48+15%=. The % converts 15 to 15% of 48 = 7.20, giving 48+7.20=55.20. For discount: 120−20%= gives 120−24=96. To find what percent one number is of another: enter the part, press ÷, enter the whole, press %.
a + b% = a + (b/100 × a) | a − b% = a − (b/100 × a)$48 + 15% tip = $55.20 | $120 − 20% discount = $96Full keyboard support: 0-9 for digits, + − * / for operators (asterisk and slash map to × and ÷), Enter or = for result, Backspace to delete one digit, Escape to clear. Period or comma for decimal point. This makes the calculator as fast as a physical calculator for experienced users.
Keys: 0-9, +−*/, Enter=result, Backspace=delete, Esc=clearType: 1234.56+789.01 then Enter → result 2023.57Every completed calculation (pressing = or Enter) saves to the history panel below the buttons. The history shows the full expression and result. Click any entry to recall that result to the display for use in the next calculation. History persists during the session and is useful for catching entry errors.
History: expression → result, click to recallHistory shows: "125 × 8 = 1000" → click → display shows 1000Quick Reference
Common calculations — verify these in the calculator above.
Multiply
125 × 8
1,000
% tip
$48 + 15%
$55.20
% discount
$120 − 20%
$96
Square root
√144
12
Memory
M+: 12.50, 8.99, 3.75
MR = 25.24
Divide
1000 ÷ 7
142.857…
Chain order
2+3×4= (chain)
20
Keyboard
Backspace key
Delete last digit
Tips & Shortcuts
Use the keyboard for long calculations — typing 1234+5678 and pressing Enter is faster than clicking 8 buttons. The keyboard maps * to × and / to ÷.
Chain memory to add up a grocery list: enter each price and press M+ after each one, then press MR at the end for the total — no running total in your head needed.
For a tip calculation: bill amount + tip percentage + % button + = gives the total. Example: 48+15%=55.20.
Use ⌫ (Backspace) to fix a mistyped digit without clearing the whole calculation — delete just the last digit entered.
The history panel is your audit trail — review it to catch errors before finalizing a calculation. Click any history entry to reuse that result.
Common Mistakes
Expecting PEMDAS order of operations
This is a chain calculator — it evaluates left to right. 2+3×4= gives 20, not 14. For proper mathematical order of operations (multiplication before addition), use the Scientific Calculator which follows PEMDAS.
Pressing C to clear one digit
C clears the entire calculation. To delete only the last digit, press ⌫ (Backspace). Use C only when you want to start completely fresh.
Using % to find a simple percentage of a number
The % button is relative to the previous operand. To find 15% of 200: press 200×15%=, result 30. Do not press 15%= directly — that would give 0.15, which is the decimal form of 15%.
Forgetting to clear memory between sessions
Memory persists until MC is pressed. If M+ was pressed in a previous calculation, the memory still holds that value. Check for the memory indicator or press MC before starting a new calculation that uses memory.
Entering commas in large numbers (1,000 instead of 1000)
The calculator uses commas as decimal separators in some regions. Remove any thousand-separator commas from numbers — enter 1000 not 1,000. The display automatically formats results with appropriate separators.
Frequently Asked Questions
Yes — type directly on your keyboard. Numbers 0-9, operators +, −, * for ×, / for ÷, Enter or = to calculate, Backspace to delete the last digit, Escape to clear everything. Keyboard input is identical to clicking the buttons and is often faster for long calculations.
M+ adds the displayed value to memory. M− subtracts it from memory. MR recalls the stored value to the display for use in the next operation. MC clears memory to zero. Practical use: compute subtotal 1 → M+. Compute subtotal 2 → M+. Press MR to see the running total. Memory survives across multiple calculations until MC is pressed.
This is a chain calculator — it evaluates left to right in entry order. For 2+3×4, the chain result is 20 (adds 2+3=5, then 5×4=20). For proper PEMDAS evaluation where multiplication runs before addition (correct result: 14), use the Scientific Calculator which follows full order of operations.
The % button computes a percentage of the previous operand. Sequence 200+15%: the % converts 15 to 15% of 200 = 30, making the full expression 200+30=230. To find 15% of 200 alone: press 200×15%=, result 30. To calculate a discount: press original_price×discount_percent%=, result is the discount amount.
Enter the number and press √. The result appears immediately — no need to press =. Examples: 144 → √ → 12. 225 → √ → 15. 2 → √ → 1.41421356. For a chain: press 200−√144= to get 200−12=188 in a single sequence.
The history panel below the buttons shows recent expressions and results automatically. Each completed calculation (pressing = or Enter) adds one entry: the full expression and its result. The history is useful for checking your work or reusing a previous result. Click any history entry to restore that result to the display.
The Basic Calculator is a chain calculator for everyday arithmetic — fast, simple, and keyboard-friendly. The Scientific Calculator adds trig functions (sin, cos, tan), logarithms (log, ln), exponents, constants (π, e), memory functions, and full PEMDAS order of operations. Use Basic for shopping, splitting bills, and simple math; use Scientific for engineering, physics, and algebra.
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