678 ROUNDED TO THE NEAREST HUNDRED IS 700. 6 is the hundreds, 7 is the tens, and 8 is the ones. It's 700 because 78 is higher than 50, so you would round up to 700. If the number was below 50 though, then you would round down. So if we say round 648 to the nearest 100, then the answer would be 600.
