The phrase "a number of contexts" is correct and usable in written English.
It can be used when referring to multiple situations or circumstances in which something is applicable or relevant.
Example: "The theory can be applied in a number of contexts, including education, business, and healthcare."
Alternatives: "various contexts" or "multiple contexts".
You see this in a number of contexts.
Like Elvis Costello, he's a great songwriter who presents his songs in a number of contexts.
(That's a point that Assange, too, might need to remind himself of, in a number of contexts).
Has the News of the World made a practice of publishing doctored photographs in a number of contexts?
Online marketers look at your behavior in a number of contexts to sell you something you may not even know you wanted.
"I just did a search for the word 'reasonable' in one of the standard proprietary leases," he said, "and the word comes up over and over again in a number of contexts".
The Justice Department sends Congress a letter insisting that the business records provision addresses a gap in intelligence collection authorities and has proven valuable in a number of contexts … [including] important and highly sensitive intelligence collection operations.
With Mingus, Mr. McPherson's gift for melodic invention was given a number of contexts because the bassist wrote in a variety of forms, some conventional, most not, which meant that the player had to be ready for unusual harmonic progressions, for key, tempo and metric changes and for pieces that might change direction when Mingus shouted out instructions.
Connect to Today: In the decades since the Blitz, the term "blitz" and "blitzkrieg" have become neologisms, commonly used in a number of contexts, from advertising to law enforcement operations to sports, to describe a combination of overwhelming force and speed.
(For starters, I can imagine the new gift feature being used in a number of contexts).
The process of spray drying is applied in a number of contexts.
