It has no precision, since there is no following number.
Always the last number, so in this example the precision is to hundredths.
The farthest to the right.
The last digit, 2.
In this case with 234.896 the last digit, '6' determines the precision since in is the last non-zero digit.
If a number is given to the true degree of precision, this is always determined by its last digit - in this case, 6.
None of them, you do that! You have given it to the precision of 3 decimal places or 6 significant figures however.