19 halves as a decimal is 9.5.
Three halves is one and a half, or 1.5 when written as a decimal.
To turn a mixed fraction into a decimal, you need to treat the fraction part as if it were a division. In this case we have 50 halves or 50/2. Dividing this gives 25. This is then added to the whole part (35) to give 60. So 35 and 50 halves as a decimal is 60.
2.0 is the decimal of four halves
2.5
3.5
1.5.
1.5
2.0
25 of them because 25/2 = 12.5
Two halves = 2*0.5 = 1 (or 1.0, if you must)
15 / 2 = 7.5