1 Historical review: Some topics are better understood if a brief historical review of the topic is presented to lead into the discussion of the moment. Such topics might include "a biographical sketch of a war hero," "an upcoming execution of a convicted criminal," or "drugs and the younger generation." Obviously there are many, many more topics that could be introduced by reviewing the history of the topic before the writer gets down to the nitty gritty of his paper. It is important that the historical review be brief so that it does not take over the paper.
The Chicago Manual of Style recommends spelling out the numbers zero through one hundred and using figures thereafter—except for whole numbers used in combination with hundred , thousand , hundred thousand , million , billion , and beyond (., two hundred ; twenty-eight thousand ; three hundred thousand ; one million ). In Chicago style, as opposed to AP style, we would write four hundred , eight thousand , and twenty million with no numerals—but like AP, Chicago style would require numerals for 401 ; 8,012 ; and 20,040,086 .