Finx Academy
Eight answers, one sheet, sixty seconds to beat. Every one is a single function over the numbers in front of you.
This is practice, not a test.
Retake any drill as often as you like — there is no limit and no waiting. Nothing here is scored, nothing is recorded against you, and getting quicker because you have seen it before is the drill working rather than a way around it. The only number is how long it took. The timed test is the one that is scored.