450 is exactly midpoint between 400 and 500.
Both of these two figures are the nearest hundreds, especially when compared with options such as 200, 300, 600, 700 etc!
For expedience, it is fairly common to round upwards a figure that is halfway.
In this case, 450 would be rounded up to 500.
But in some fields it is the practice to round down all figures which do not exceed the halfway point. If this is the required approach, then 450 would be rounded down to 400 as being the 'nearest' hundred.
However, in either case, when the figure/sum/amount is exactly at the half way point, then both the upper and the lower options are the 'nearest,' both being exactly the same 'distance' away from the amount in question.
e.g.
500
Anything from 450 to 549
3400
400
Oh, dude, you're hitting me with the big math questions, huh? Okay, so, like, when you round 450, you're looking at the digit right after the 5, which is 0. And since 0 is less than 5, you just leave the 5 as is. So, 450 rounded is still just 450. Easy peasy, right?
Round it up to 500.
The nearest hundred to 3,490 is 3,500.
It is: 500
500
One answer is 450
450
500
Numbers from 450 to 549.
It is 500.
Anything from 450 to 549
It is 400 because 402 is less than 450
Any from 450 to 549