Arabic numerals Libya to Morocco. Arabs, on the other hand, call the base-10 system (not just these digits) "Hindu numerals", referring to their origin in India. This is not to be confused with what the Arabs call the "Hindi numerals", namely the Eastern Arabic numerals ( - - - - - - - - - ) used in the Middle East, or any of the numerals currently used in Indian languages (e.g. Devanagari: ). The European acceptance of the numerals was accelerated by the invention of the printing press, and they became widely known during the 15th century. Early evidence of their
Numerals in Unicode three Unicode characters semantically represent mathematical constants: , the , and . Other mathematical constants can be represented using characters that have multiple semantic uses. For example, although Unicode includes a character for "natural exponent" ℯ (U+212F) its UCS canonical name derives from its glyph: ; and the mathematical constant π, 3.141592.., is represented by . The Western Arabic numerals also appear among the compatibility characters as rich text variant forms including bold, double-struck, monospace, sans-serif and sans-serif bold. and fullwidth variants for legacy vertical text support. Rich text parenthesized, circled and other variants are also included in the blocks: