Answer :
you take the second decimal, and if it is 5 or over, you increase the first decimal by one. If the number is 17.96,you increase the first decimal by one which gives you 18. If the question asks for 1 decimal place, than put 18.0 :)
when rounding off numbers to specific decimal places look at the number after that place. If that number is less than 5 then keep the needed decimal the same. if it is greater than 5 then round up by one.
Examples:
15.69 ⇒ 15.7
15.64 ⇒ 15.6
17.890 ⇒ 17.89
17.898 ⇒ 17.90
