Chapter 16 Num. & Percentages

16.1 numbers
*Numbers should only be spelled out using letters if they are under 11. (e.g. 125 qustionaires)
*If a number begins the sentence, then it must be spelled out regardless of its value. (e.g. Fourteen theories)
*Numbers and letters should not be mixed when writing out a number. (e.g. 150 thousand -> 150,000)
*When spelling out exact numbers, ‘hundred’, ‘thousand’, and ‘million’ should not be made plural even if their unit value is more than one. 
16.2 sequence adj. that include a num. 
*The number must go after sequence words such as ‘first’, ‘next’, and ‘last’. e.g. next three cases 
*But go before any other modifying word. e.g. two main contributions 
16.3 ordinal numbers 
11st -> 11th, twelvth -> twelfth, 40th = fortieth, 4th = fourth
16.4 rank & article
*When referring to a particular rank, a definite article is normally used. e.g. the first problem is
*While used as an adverb that expresses the order of a list of points, no article is required. e.g. first, …, second
16.5 fractions
*two-thirds, three-quarters
16.6 prep. for num.related phrases
*be divided by 被……除以
*be equal to, equals
16.7 percentages
*The percentage sign (%) is preferred to words when using percentages in the main text. e.g. low that 60%
*If the sentence begins with a percentage, then the term should be written without numbers or signs. e.g. seventy percent
*a small percentage, written in percentages
*When providing percentages in the results section, the ‘of phrase’ is likely to be needed. e.g. twenty percent of the teachers
*When the percentage is acting like an adjective, then the ‘of’ phrase will not be required. e.g. 68% success rate
*20% of the patients are…, 25% of the training is…
*fewer than 20% of the patients, less than 25% of the training