How many decimal points do you want displayed? Do want trailing 0 to pad to that length?
Assuming you want 4 decimals then a custom format such as this should work. Make sure the data is read as numeric not character.
proc format library=work;
picture MyDec
low -<0 = '0009.9999'(prefix='-')
0 - high= '0009.9999'(prefix='+');
run;
data have;
input x ;
datalines;
+0.0125
+7.90
-0.0076
-0.5
;
run;
proc print data=have;
format x MyDec.;
var x;
run;