a=%w(one two three four five six seven eigh nine)
b=%w(thir four fif)+a[5,4]
a[7]+='t'
puts'zero',a,%w(ten eleven twelve),b.map{|d|d+'teen'},['twen',*b].map{|d|[s=d.delete('u')+'ty',a.map{|t|s+' '+t}]},'one hundred'
Note that non-ascii characters in the above source code will be escaped (such as \x9f).