round 1.998 to the four decimals as needed = 1.9980
All of them from 0.0450 to 0.0549 . That's 99 of them, but I think 98 is a better answer, because 0.0500 wouldn't need to be rounded at all.
40.04
8.4
8.4
0.4
There are 99 of them - using the IEEE standard of rounding half to even
4.16
Four hundred ninety thousandths in decimals is 0.490
0.04 is.
All of them from 0.0450 to 0.0549 . That's 99 of them, but I think 98 is a better answer, because 0.0500 wouldn't need to be rounded at all.
4.25
40.04
0.4
4.75
0.16
8.4
8.4