In MLA format, the best practice is to spell numbers that can be written in one of two words. Examples are: one million, or one-half. For more complicated numbers, or numbers that require more than two words, type them. Examples could be: 365, 5.76, or 2 1/2.
In terms of number ranges: always type them in as Arabic numbers. Examples include: 395-401, 222 BCE-180 BCE, 1952 to 1965.
All attempts should be made to avoid pronouns that exclude people based on gender. To do this you could choose both masculine and feminine pronouns or use the plural nouns and pronouns (their).
Example: When a student attends community college, he or she is giving one's self a chance at a better life.
Example: When students attend community college, they give themselves a chance at a better life.
MLA guidelines encourage the use of the "their" pronoun with person who do not identify by a male/female binary. Writers can also use the plural "their" pronoun if they are writing about a person whose gender is unknown.
Although, it may be considered undesirable to match a singular noun with a plural pronoun, you may want to check with your professor about whether this is acceptable in cases where more specific language would be less inclusive and make certain unfair assumptions about one's gender or identity.