Repeating decimal AutoCorrect

We are working with decimal representations of fractions. A question I am asking is “What is the decimal representation of 1/6?” I would want them to enter the answer using either ellipsis notation (0.1666…) or better yet using a vinculum (bar). I want to auto correct this. Ideas? (Other than rounding or asking them to just give a certain number of decimal places.)

Not sure how desmos will deal with the ellipsis, but mulltiple countNumberUsage checks is the only other way I see.