notation for precision or number of decimals If you have a formula like $x = y+2.1234$, is there a way to specify $y$ should have no more than 2 decimals? So if $y = 12.1234$ then you should use 12.12 when using this formula.

Same for the result, is there a way to specify you only should use the first 2 decimals of $y$ and discard the rest?

To clarify: it is for documentation purposes. I need to document a value should only have 2 decimal places and the rest should be discarded.
So when I have a complex formula $x = ....$, is there any notation possible which shows to use only 2 decimals of $x$?
You can write $12.1\bar{2}$ or $12.1\underline{2}$.

edit: I saw this notation on the Khan Academy videos for significant figures.
(He says that it's more common to write the answer in scientific notation and then the precision is implied by how many digits are after the decimal, though).
You can write $12.1\bar{2}$ or $12.1\underline{2}$.

edit: I saw this notation on the Khan Academy videos for significant figures.
(He says that it's more common to write the answer in scientific notation and then the precision is implied by how many digits are after the decimal, though).