Basic Calculator
A simple calculator for everyday arithmetic — addition, subtraction, multiplication, and division.
Cómo funciona
This is a straightforward four-function calculator for everyday arithmetic: addition, subtraction, multiplication, and division, with support for decimals and negative numbers. Type or click digits and operators to build an expression, then press = to evaluate it.
Expressions follow standard order of operations (also called PEMDAS or BODMAS): multiplication and division are evaluated before addition and subtraction, and any parentheses in the expression are evaluated first, overriding the default order. For example, 2 + 3 × 4 evaluates to 14 (the multiplication happens first), not 20 (which would result from evaluating strictly left to right).
This distinction matters more than it might seem — a huge number of "wrong calculator answer" confusions online come down to a misunderstanding of order of operations rather than an actual calculator bug, since different ways of reading the same string of numbers and symbols can genuinely produce different valid-looking results depending on which rule you apply.
The calculator supports full keyboard input in addition to on-screen buttons: number keys and operator keys work as expected, Enter acts as the equals button, and Backspace or Escape can correct or clear an entry — useful for quickly running numbers without reaching for the mouse.
For calculations beyond the four basic operations — trigonometry, logarithms, exponents, or square roots — the Scientific Calculator extends this same interface with those additional functions, while staying just as fast for simple arithmetic when that's all you need.
A basic calculator like this one covers the vast majority of everyday number-crunching: splitting a bill, adding up a shopping list, checking a percentage by hand, or verifying a quick calculation before committing to it in a more important context like a budget or invoice.
Even though a calculator does the arithmetic instantly, understanding order of operations still matters for reading any written expression correctly — on paper, in a spreadsheet formula, or in a textbook problem — since the calculator simply automates a rule that applies whether or not a machine is involved. Knowing why 2 + 3 × 4 = 14 rather than 20 helps catch data-entry mistakes when a result looks unexpectedly off.
Does it follow order of operations?
Yes — multiplication and division are evaluated before addition and subtraction, and parentheses are respected.
Can I use my keyboard?
Yes, number and operator keys, Enter for equals, and Backspace/Escape all work.
Why did I get a different answer than I expected?
The most common cause is order of operations — multiplication and division are always evaluated before addition and subtraction, which can produce a different result than reading the expression strictly left to right.
Can this calculator handle negative numbers?
Yes — negative numbers and results are fully supported in all four operations.
Does it support decimal numbers?
Yes — enter a decimal point as part of any number for calculations involving fractional values.
What happens if I divide by zero?
Division by zero is undefined in standard arithmetic — the calculator will indicate an error rather than return a numeric result.
Is there a limit to how large a number I can calculate with?
Practically, extremely large numbers may lose precision or display in scientific notation, but everyday arithmetic well beyond typical use cases is fully supported.
When should I use the Scientific Calculator instead?
When you need trigonometry, logarithms, exponents, or square roots — this basic calculator covers the four fundamental operations, while the Scientific Calculator adds those additional functions.
Why do PEMDAS and BODMAS refer to the same rule?
They're regional teaching acronyms for identical order-of-operations rules — PEMDAS (Parentheses, Exponents, Multiplication/Division, Addition/Subtraction) is common in the US, while BODMAS (Brackets, Orders, Division/Multiplication, Addition/Subtraction) is common in the UK and other countries.
Does the calculator round results automatically?
Results display with reasonable precision for everyday use; very long decimal results may be truncated for readability without affecting the underlying calculation.