SYMBOL SET REFERENCE
Type ±, ×, ÷, °, ², ³, √, ∞, ≈, ≠, ∑ without a math editor.
Basic operators first. ± (Alt+0177) is the plus-or-minus, essential for statistics and engineering tolerances: "5.2 ± 0.3." × (Alt+0215) is the proper multiplication sign, visually distinct from lowercase x. ÷ (Alt+0247) is the division sign, more formal than slash. ° (Alt+0176) is the degree sign, for temperatures (20°C) and angles (90°).
Superscripts for exponents. ² (Alt+0178), ³ (Alt+0179), ¹ (Alt+0185). Useful for "m²" (square meters), "10³" (thousand), or "e⁻¹" (though ⁻ requires Unicode). For superscripts beyond 1, 2, 3 you'll need Unicode: ⁰ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹.
Greek letters for math conventions. Physics and engineering use Greek letters extensively: π for pi, α for angles/alpha particles, β for beta, Ω for ohms, Σ for summation, Δ for change/delta, λ for wavelength. See the dedicated Greek alphabet page for all codes.
µ (micro / mu). µ (Alt+0181) is technically the Greek letter mu but doubles as the SI prefix "micro" (one millionth): µm (micrometer), µA (microamp), µs (microsecond). There's a distinct Unicode "micro sign" (U+00B5) and "Greek mu" (U+03BC) — they look identical but are different characters. For SI prefixes, use µ (Alt+0181, micro sign).
Comparison operators (Unicode). ≈ "approximately equal to" (U+2248), ≠ "not equal to" (U+2260), ≤ "less than or equal" (U+2264), ≥ "greater than or equal" (U+2265). These matter for inequalities in stats and analysis. Alt+X method: type the hex code in Word, press Alt+X.
Set theory and logic (Unicode). ∈ "element of" (U+2208), ∉ "not element of" (U+2209), ⊂ "subset" (U+2282), ⊃ "superset" (U+2283), ∪ "union" (U+222A), ∩ "intersection" (U+2229). ∀ "for all" (U+2200), ∃ "there exists" (U+2203). Essential for discrete math and proofs.
Calculus and operators (Unicode). ∑ summation (U+2211), ∏ product (U+220F), ∫ integral (U+222B), ∂ partial derivative (U+2202), ∆ delta/change (U+2206), ∇ nabla/gradient (U+2207), √ square root (U+221A), ∞ infinity (U+221E).
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