It's important to note that the numbers from 1 to 9 have 2 different pronunciations for different contexts. Usually when you're just counting up you can use the On versions of the numbers. In your case that would mean 4 = shi and 7 = shichi instead of their Kun versions yon and nana. The Kun versions are mostly used when you quantify something. For example listing things you would use yon instead of shi, but also futatsu instead of ni.
Though your version is fine too. I hope your teacher already told you that there are two versions.
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