Although people in many parts of the world share common alphabets and numeral systems (versions of the Latin writing system are used throughout the Americas, Australia, and much of Europe and Africa; the Arabic numerals are nearly universal), styles of handwritten letterforms vary between individuals, and sometimes also vary systematically between regions. Arabic numerals The handwritten numerals used in Western countries have two common forms: "In-line" or "full-height" form is similar to that used on typewriters and is taught in North America; in this form all numerals have the same height as the majuscule alphabet (i.e. the capital letters). In "old style" text figures, numerals 0, 1 and 2 are x-height; numerals 6 and 8 have bowls within x-height, plus ascenders; numerals 3, 5, 7 and 9 have descenders from x-height, with 3 resembling ; and the numeral 4 extends a short distance both up and down from x-height. Old-style numerals are often used by British presses. Aside from these two main forms, other regional variations abound. The numeral 0: Some writers put a diagonal slash through the numeral 0 (zero), a practice that was used on some early, low-resolution computer terminals which displayed a slashed "zero" glyph to distinguish it from the capital letter O. This practice conflicts with the use of the letter "Ø" in the Danish and Norwegian languages, and the empty set character "∅" used in set theory. Forms that avoid confusion with Danish include: a dot placed in the centre of zero, but needing to be distinguished from monocular O (Ꙩ/ꙩ), the bilabial click letter (ʘ), or the Gothic letter hwair (𐍈) the use of a tick, that is, a slash that does not cross the entire bowl of the figure, but lies completely in the upper right a form found in Germany with a vertical slash a form with a slash from upper left to lower right. Confusion between the numeral 0 and the letter O can be resolved by using a script letter O (with a loop at the top). The numeral 1: This numeral is sometimes written with a serif at the top extending downward and to the left. People in some parts of Europe extend this stroke nearly the whole distance to the baseline. It is sometimes written with a horizontal serif at the base; without the serif it can resemble the shape of the numeral 7, which has a near-vertical