For example, writing down "two" instead of "2". Which one is better to use throughout a book. Plus, which one should be used in the following situations. Age Height (six feet one vs 6 ft 1) Grade (school grade. e.g. gr1, gr2, gr3...) Date Money Number of something Measurement (20 cm vs twenty cm) Weight (200 lbs vs two hundred pounds) Plus if you could add any other situation I might have missed (I know I missed a lot), it would be greatly appreciated. Thanks.