Which is correct, in each number, or on each number or for each number? I need to ask questions mentioning that each number has a different instruction. Any help that includes sentence examples will be so appreciated. Thanks in advance. English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It only takes a minute to sign up. Sign up to join this communityContext is king, all of your phrases can be grammatically correct: In each number from twelve to ninety-nine, the letter "t" appears at least once. When playing hopscotch, you start the game by jumping on each number in numerical order. For each number which contains a 3 or is divisible by 3, say "Fizz" instead of the number.