We write .5 or 0.5 as the decimal for one half.
12 and one half as a decimal is 12.5
1.5
11/2% = 0.015
1/2% = 0.0050
1.5
1.5"
The decimal form of 1/2 is 0.5
0.5
0.5
1.5
.5
1.5
Half a milligramme = 0.5 milligramme
that would be .075 in decimal form
.0005
0.5 mm