
Scientific notation (also referred to as standard form or standard index form) is a way of expressing numbers that are too big or too small to be conveniently written in decimal form. It is commonly used by scientists, mathematicians and engineers. On scientific calculators it is known as "SCI" display mode. In scientific notation all numbers are written in the form :''m'' × 10 (''m'' times ten raised to the power of ''n''), where the exponent ''n'' is an integer, and the coefficient ''m'' is any real number (however, see normalized notation below), called the ''significand'' or ''mantissa''. The term "mantissa" may cause confusion, however, because it can also refer to the fractional part of the common logarithm. If the number is negative then a minus sign precedes ''m'' (as in ordinary decimal notation). Decimal floating point is a computer arithmetic system closely related to scientific notation. ==Normalized notation== (詳細は In ''normalized'' scientific notation, the exponent ''n'' is chosen so that the absolute value of ''m'' remains at least one but less than ten (1 ≤ ''m'' < 10). Thus 350 is written as . This form allows easy comparison of numbers, as the exponent ''n'' gives the number's order of magnitude. In normalized notation, the exponent ''n'' is negative for a number with absolute value between 0 and 1 (e.g. 0.5 is written as ). The 10 and exponent are often omitted when the exponent is 0. Normalized scientific form is the typical form of expression of large numbers in many fields, unless an unnormalized form, such as engineering notation, is desired. Normalized scientific notation is often called exponential notation—although the latter term is more general and also applies when ''m'' is not restricted to the range 1 to 10 (as in engineering notation for instance) and to bases other than 10 (as in ). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「scientific notation」の詳細全文を読む スポンサード リンク
