1.83 is 1.8 when rounded to one decimal place. The reason for this is the rule of thumb where 1 to 4 you round down, 5 to 9 you round up, in your case it's 3, thus you round down.
It is already rounded to exactly that degree.
49.72 rounded to one decimal place is 49.7.
It is 44.3 when rounded to one decimal place
3.48 rounded to one decimal place is 3.5.
3.05 rounded to one decimal place is 3.1.
It is already rounded to exactly that degree.
49.72 rounded to one decimal place is 49.7.
It is 44.3 when rounded to one decimal place
It is then 5.7 when rounded to one decimal place
978.229 rounded to one decimal place is 978.2
It is 0.5 when rounded to one decimal place.
3.48 rounded to one decimal place is 3.5.
3.05 rounded to one decimal place is 3.1.
44.98 rounded to one decimal place is 45.0
13.3131 rounded to one decimal place = 13.3
2.91 rounded to one decimal place is 2.9
1.13 rounded to one decimal place is 1.1