The Mathematical Operators block runs from U+2200 to U+22FF and holds 256 codepoints. It is mathematics' main address inside Unicode: ∀, ∃, ∈, ⊂, ∪, ∩, ∫, ∂, ∇, ∞, ≠, ≤, ≥, ≡, ≈ — the working vocabulary of every modern mathematical text — are here, lined up in a single contiguous range.
About this block
The block was added in Unicode 1.0 (1991) and substantially expanded in Unicode 3.2 (2002), when STIX (the Scientific and Technical Information Exchange) project pushed for fuller math coverage. STIX, a collaboration of the American Physical Society, American Mathematical Society, IEEE, Elsevier, and others, gave Unicode many of the operators it needed to typeset journal-quality mathematics without resorting to private encodings or TeX-only conventions. Today this block, together with the Supplemental Mathematical Operators block (U+2A00–U+2AFF) and the various math letterforms in U+1D400–U+1D7FF, covers nearly the entire mathematical character set used by professional typesetters.
Not every math symbol you might reach for lives here. The basic arithmetic operators — plus +, hyphen-minus -, equals =, less-than <, greater-than > — sit in Basic Latin because they were inherited from ASCII. The proper mathematical minus, distinct from the hyphen-minus, is here as U+2212 MINUS SIGN; the proper division sign is in Latin-1 Supplement as U+00F7. Arrows used as mathematical relations live in Arrows: → is U+2192, ⇒ is U+21D2. And the script and double-struck math letters (ℝ ℂ ℕ 𝒜 𝔄) are split between Letterlike Symbols and the Mathematical Alphanumeric Symbols block on Plane 1.
The block organizes itself in rough functional groups. The first row, around U+2200–U+220F, holds logic and quantifier symbols (∀, ∁, ∂, ∃, ∄, ∅, ∆, ∇) and the big operators (∏ ∑ ∐). Square roots and proportionality follow at U+221A–U+221F. Set membership and inclusion cluster around U+2208–U+220D (∈ ∉ ∋ ∌). Integrals occupy U+222B–U+2233 (∫ ∬ ∭ ∮). Relations dominate the second half — ≠ ≡ ≤ ≥ ≪ ≫ ⊂ ⊃ ⊆ ⊇ ⊕ ⊗ — followed by ordering and tensor operators in the U+22xx range. Logical AND/OR appear as ∧ U+2227 and ∨ U+2228.
Two operational notes are worth flagging. First, many "lookalikes" actually have distinct codepoints with distinct Unicode properties: ∗ ASTERISK OPERATOR (U+2217) is not the same as * ASTERISK (U+002A); ⋅ DOT OPERATOR (U+22C5) is not the same as · MIDDLE DOT (U+00B7). Second, MathML and TeX typesetters use the proper math operators (with their math-class properties from the Unicode Math Property file) to determine spacing; substituting ASCII fallbacks produces visibly wrong output.