there are several ways, 11/2 would be the main one though.
1/2 1:2 .5 one half One half, 0.5, 1/2, 50%.
7 1/2 hrs or 7.5 hrs. or 7 hours 30 minutes.
1/2
One and a half meter is written as 1 1/2 meters or 1.5 meters.
1/2 of 1/100 = 1/200
1/2 hour 30 minutes 0.5 hours
1/2
1 1/2
1/2 1:2 .5 one half One half, 0.5, 1/2, 50%.
7 1/2 hrs or 7.5 hrs. or 7 hours 30 minutes.
1/2
0.5%
1.5
1/2 = .5 1/2 is a half a whole, and one whole number is 1. so half is 0.5
One and a half meter is written as 1 1/2 meters or 1.5 meters.
1 and one half billion can be written as 1.5 billion.
You could write 2 1/2 or 2.5.