±
Plus-Minus Sign
The plus-minus symbol (±) indicates mathematical uncertainty, measurement tolerance, and dual solutions, essential for scientific accuracy and statistical analysis.
Technical Details
- ASCII Code
- 177
- HTML Entity
- ±
- Hexadecimal
- 0xB1
- Binary
- 10110001
- Octal
- 261
Usage & Examples
Programming
char symbol = '±'; // ASCII 177HTML/Web
± or ±Common Uses
How to Type This Character
Windows
Mac
💡 Pro tip: The fastest way is to bookmark this page or copy the character from our ASCII library!
Related Characters
About the Plus-Minus Sign
Measurement Uncertainty
Critical for expressing precision limits in scientific measurements, manufacturing tolerances, and quality control. The symbol enables accurate communication of acceptable variation ranges in engineering and research contexts.
Statistical Applications
Essential for confidence intervals, margin of error, and standard deviation notation in statistics. Appears in polling data, scientific studies, and quality assurance where uncertainty quantification is crucial.
Mathematical Solutions
Indicates dual solutions in quadratic equations (x = -b ± √(b²-4ac)/2a) and other mathematical contexts where multiple valid answers exist. Fundamental to algebraic problem-solving and equation analysis.
Scientific Notation
Used throughout physics, chemistry, and engineering to indicate experimental uncertainty and measurement precision. Essential for maintaining scientific accuracy and reproducibility standards.
History of the Plus-Minus Sign
Mathematical Innovation
Albert Girard first used ± notation in mathematical texts to indicate both positive and negative solutions, establishing the symbol's role in algebraic notation.
Scientific Measurement
Scientists began using plus-minus notation to express measurement uncertainty and experimental error, creating standards for scientific accuracy and precision.
Statistical Development
Early statisticians adopted ± for expressing confidence intervals and data uncertainty, laying groundwork for modern statistical analysis methods.
Quality Control
Industrial manufacturing adopted plus-minus tolerances for product specifications, ensuring quality standards and interchangeable parts in mass production.
Computer Integration
Early computer systems included ± in character sets for scientific computing and engineering applications, enabling digital precision specification.
Cultural Impact
The plus-minus symbol represents scientific honesty about uncertainty and precision, enabling accurate communication of measurement limitations that supports reliable scientific knowledge and engineering safety.
Usage Examples
Scientific Measurements
ExampleLaboratory precision and experimental uncertainty
Manufacturing Tolerances
ExampleQuality control and production specifications
Mathematical Solutions
ExampleAlgebraic problem solving and equation solutions
Statistical Reporting
ExamplePolling accuracy and statistical analysis