Marking a repeating decimal when it's written with a set number of places

Question

I'm typesetting some film related material that contains a list of common aspect ratios:

• 1.33
• 1.66
• 1.77
• 1.85
• 2.35

And this is exactly how they are usually displayed, using two decimals.

Now, the ratios 1.33, 1.66 and 1.77 all have a single repeating decimal (they're expansions of 4/3, 5/3 and 16/9), so technically the latter two should be rounded to 1.67 and 1.78. However, they're usually just truncated because it looks better.

I'd like to keep that format and was wondering whether I can put an overline or a dot over either both decimals or just the last one, as a nice little touch.

I'm guessing that $1.\overline{66}$ wouldn't be correct, because it's only one digit that's repeating, not the pair. But what about $1.6\overline{6}$? It seems logical, but I've never seen a single repeating decimal written that way.

Answer 1

I have never seen mixing of the overline and truncation/rounding.

The overline is an improvement over truncation even though less often used.

$1.6\overline{6}$ or $1.\overline{66}$ then have no benefits over $1.\overline{6}$.