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The significant figures of a number are digits that carry meaning contributing to its measurement resolution. This includes all digits ''except'':〔''Chemistry in the Community''; Kendall-Hunt:Dubuque, IA 1988〕 * All leading zeros; * Trailing zeros when they are merely placeholders to indicate the scale of the number (exact rules are explained at identifying significant figures); and * Spurious digits introduced, for example, by calculations carried out to greater precision than that of the original data, or measurements reported to a greater precision than the equipment supports. Significance arithmetic are approximate rules for roughly maintaining significance throughout a computation. The more sophisticated scientific rules are known as propagation of uncertainty. Numbers are often rounded to avoid reporting insignificant figures. For example, it would create false precision to express a measurement as 12.34500 kg (which has seven significant figures) if the scales only measured to the nearest gram and gave a reading of 12.345 kg (which has five significant figures) . Numbers can also be rounded merely for simplicity rather than to indicate a given precision of measurement, for example to make them faster to pronounce in news broadcasts. ==Identifying significant figures== 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「Significant figures」の詳細全文を読む スポンサード リンク
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