(will mark brainliest, double points) when should a number be written using words instead of digits?

MLA Style says numbers that can be written in one or two words (three, fifteen, seventy-six, one thousand, twelve billion) and to use numerals for other numbers (2¾; 584; 1,001; 25,000,000). APA Style,  uses words for numbers below 10 and numerals for numbers 10 and above.

a biography is a genre that mainly accounts somebody's life and that is written by somebody else. this genre supports sonia nazario's desire to share enrique's life because she can fully inform readers of his entire emotional journey.

in a biography, an author can share the readers almost everything about a person's life, or just one key event or personal aspect the author is interested in telling, like in this specific case in which sonia nazario is centered in enrique's emotional journey.

1. ( 3rd option ) peter gets into a fight with the musician because they will not play a happy song for him.

2. ( 2nd option) petty arguments like feuds lead to pointless tragedy .