SAS: Floating point hell

I grew up on COBOL and mainframe Assembler.  I loved packed decimal numbers because you always knew what you had.  I HATE floating point numbers.  I first stumbled upon this issue accidentally while learning C.  The same issue exists in Java.  And SAS. 

I don't have time to elaborate right now.  So I just want to capture the problem.  Here is the SAS log.  compare variables (e and f), (c and h), and (b and g).  In particular, note my use of +1.E-10. Warning ... +1.E-11 gives different results.

1    data _null_;
2    a = 400.4444;
3    i = 4;
4    b = int(a * 10 ** i) / (10 ** i);
5    c = (a = b);
6    d = a * 10 ** i;
7    e = int(a * 10 ** i);
8    f = int(a * 10 ** i + 1.E-10);
9    g = int(a * 10 ** i + 1.E-10) / (10 ** i);
10   h = (a = g);
11   put a= i= b= c= d= e= f= g= h=;
12   run;

a=400.4444 i=4 b=400.4443 c=0 d=4004444 e=4004443 f=4004444 g=400.4444 h=1