999.9 rounded to the nearest tenth is 1000. When rounding a number to the nearest tenth, you look at the digit in the hundredths place. If it is 5 or greater, you round up; if it is less than 5, you round down. In this case, 999.9 has a hundredths place digit of 9, which is 5 or greater, so it rounds up to 1000.
9999 rounded to the nearest tens place is 10,000
10000
It is then 52.8 when rounded to the nearest tenth
It is then 56.5 when rounded to the nearest tenth
It is 232.4 when rounded to the nearest tenth
It is then 20.2 when rounded to the nearest tenth
It is 0.8 when rounded to the nearest tenth
4.4
10775.9
2.7
54.4
28.6