Learn English – How to say: “this number has not been rounded”

In English, one would normally say "dozens of" rather than "tens of", so there is some overlap. I might use "dozens of" for an amount between 36 (a dozen, two dozen, dozens...) and 132 (a dozen less than a gross), "scores of" for a number between 40 and 199, and "hundreds of" for values greater than that. I don't think I've ever thought about the reasoning behind this; it would really depend on which number sounded better in the areas which overlap.

You would say place instead of position, and you would drop the number entirely:

3 is in the hundreds' place

5 is in the ones' place

You could go on in the same way with all the other places: '1' is in the ten thousands' place, or in the number 7.86, 8 is in the tenths' place.

Another alternative is use the word "digit":

3 is the hundreds' digit.

5 is the ones' digit.