hi <3
1) as the value ahead of the tenths position is a 5, you would round up.
this gives you the answer of 1.6
2) as the value ahead of the hundredths position is a 4, you would round down.
this gives you the answer of 1.55
3) as the value ahead of the thousandths position is an eight, you would round up.
this gives you the answer of 1.555
hope this helps :)