Student checking arithmetic
Enter expressions naturally and understand precedence.
Type or paste an expression, choose angle mode, evaluate, and restore a recent in-session expression.
Can reproduce right-associative power and unary-minus behavior.
Evaluate typed or button-built arithmetic, powers, trigonometry, logarithms, roots, and constants with a bounded no-eval parser and explicit degree/radian mode.
A quick decision brief for this specific tool
A typed, pasted, or button-built expression up to 500 characters using documented operators/functions/constants and an explicit degree or radian mode
One finite IEEE 754 numeric result plus up to ten in-session history entries and optional memory value
A bounded no-eval recursive-descent parser with right-associative powers, unary precedence, strict scientific notation, function-domain validation, and singular-tangent rejection
Choose your path
Evaluate a bounded, documented real-number expression consistently from typing or buttons without eval, permissive token parsing, or hidden angle assumptions.
Enter expressions naturally and understand precedence.
Type or paste an expression, choose angle mode, evaluate, and restore a recent in-session expression.
Can reproduce right-associative power and unary-minus behavior.
Edit and evaluate without relying on the button grid.
Focus the expression input, type/paste, use Enter to evaluate and Escape to clear.
Receives the same strict result and domain handling as button input.
Know numeric and unit limits before relying on a result.
Review IEEE 754, supported grammar, angle, constant, and no-dimensional-analysis disclosures.
Moves symbolic, arbitrary-precision, complex, or unit-aware work to an appropriate system.
This tool is part of these guided projects. Each project provides step-by-step instructions with checklists and all the tools you need in one place.
Tools you might need next
Find the nonnegative principal real square root, labeling exact integer roots separately from rounded approximations and equation solutions.
Evaluate finite real powers with explicit rules for negative bases, zero, reciprocals, exact integers, rounding, and Number-range limits.
Evaluate a real logarithm in an explicit valid base, recognize exact integer powers, and control rounding without silent defaults.
The recursive-descent parser tokenizes at most 500 characters/tokens and applies a documented grammar. Powers associate right-to-left and bind more tightly than unary minus.
-2^2 = -(2^2) = -4; 2^3^2 = 2^(3^2) = 512sin, cos, and tan follow the selected degree or radian mode. log is base 10; ln is natural log. Functions require parentheses and invalid real-number domains return Error.
Malformed numeric literals, trailing tokens, division by zero, square roots of negative values, non-positive logarithms, non-finite results, and detected tangent singularities return Error. Constants c and g are numeric SI reference values; the tool does not perform dimensional analysis.
Updated: August 2026
A student enters sin(30) in degree mode and checks that the result is 0.5, then switches to radians for sin(pi/2).
An engineer evaluates a bounded numeric expression, aware that c and g are bare SI reference numbers and units are not tracked.
A user pastes 2e3 + sqrt(16), reviews the result, and restores a recent in-session expression without assuming arbitrary precision or permanent history.
Type, paste, or build an expression with buttons, choose degrees or radians, and evaluate it locally. The parser supports a documented finite grammar and rejects malformed numbers, unsupported implicit multiplication, division by zero, invalid domains, and tangent singularities.