1. Number collisions
In the sentence, “The day the slain woman was to turn 28, 3,000 gathered at a church to recall her life,” the proximity of her age (expressed numerically rather than spelled out) and the number of mourners confuses the eye. Readers may assume, before they comprehend the sense of the sentence, that the comma after her age and the following letter space are erroneous and that the digits belong in one figure.
Do not use the word from preceding a number range in which an en dash (or, as is employed often in newspapers and online, a hyphen) appears: “The Korean War lasted from 1950–1953” should read “The Korean War lasted from 1950 to 1953,” or “The Korean War lasted 1950–1953.” “The class will be held from 7–10 p.m.” is correctly expressed, “The class will be held from 7 p.m. to 10 p.m.,” (the first p.m. may be elided) as in, “The class will be held 7–10 p.m.”
3. Number names