from itertools import*
a=product(['*','','/','+','-'],repeat=8)
b="".join([str(i) for i in range(1,10)])
c=zip(repeat(b),a)
for d in c:
lst=[]
for e in zip(*d):
for f in e:
lst.append(f)
g="".join(lst)+"9"
if eval(g)==100: print g+"=100"
Runs in what, 10 seconds?