Rounded to the nearest hundredth, 6.277 is approximately equal to 6.28.
The first figure after the decimal point is tenths, and the second is hundredths. In thids case the hundredths are 0, but the thousands are 7 and so the hundredths are rounded up to a 1.... giving a...
16, or if you like, 16.00. Don't confuse a hundredth (0.01) with a hundred (100).
As a whole number, 3490 is already rounded to the nearest hundredth.
xxmini: 0.07
How to Round Decimals to the Nearest Tenth or Hundredth
How to Round Decimals to the Nearest Whole Number
How to Round a Decimal to the Nearest Whole Number
Rounding Numbers to the Nearest Ten - Lesson 12