Jack ran a race in 9.865 seconds.What is this time rounded to 1 decimal place?

Answer 1

To round to 1 decimal place you'll have to look at the decimal place after it (the hundredths place). In this case, 8 is in the tenths place (first decimal place) so we look at the hundredths (or second) decimal place, which is 6.

If the second number is 0-4, you do not round the first decimal place up. Ex. rounding 1.232 to the tenths place would be 1.2.

If the second number is 5-9, you round the first decimal place up. Ex. rounding 1.252 to the tenths place would be 1.3.

Here we see that our second number is 6, which is between 5 and 9, so we round up- 9.865 round to 9.9.

There are a few technicalities with the thousandths place rounding up the hundredths place, which can in turn round up the tenths place, but for the purposes of this question specifically that doesn't really matter.