The conventions within engineering, for example, may differ from those within economics.In this article, we present 10 rules or guidelines to spell out numbers.
While there are exceptions to these rules, your predominant concern should be expressing numbers consistently.
Here’s a tip: Want to make sure your writing always looks great?
numbers that represent statistical or mathematical functions, fractional or decimal quantities, percentages, and ratios examples: multipled by 5, .33 of the..., more than 5% of the sample..., a ratio of 15:1 d.
numbers that represent time, dates, ages, scores, points on a scale, exact sums of money and numerals examples: 1 hr 34 min., at am, 2-year olds, score 5 on a 12 point scale Use numbers expressed as words: a.
Example 2 Avoid: If shadowing were a factor, it would have affected the 7th and 8th stages.
Use: If shadowing were a factor, it would have affected the seventh and eighth stages. Example Avoid: 1000’s of Human Genes are Micro RNA Targets.Numbers that are not conveniently round will read better written as numerals.Scientific and technical journals, and even news reports, often adhere to the rule that only numbers less than ten should be written out in full, except when fractions or decimals are involved.Note that these rules are appropriate within the context of formal writing.Spell out numbers from one to nine for both ordinal (first, third, tenth, etc.) and cardinal numbers (1, 3, 10, etc).The rules demonstrated in the examples above are simply rules of thumb and there are exceptions to them.For example, round numbers such as hundreds, thousands, or hundred thousands should be written out in full.It is generally best to write out numbers from zero to one hundred in nontechnical writing.In scientific and technical writing, the prevailing style is to write out numbers under ten.For example, spell out any number that precedes another number expressed in numerals.Example Avoid: The difference from baseline stimulus sensitivity scores for each condition during the 3 20-min periods following baseline.