So if the numberString[] array is a String array (and [0] is actually populated with a String), and the key of the HashMap is a String.... and 'number' is an Integer..... and the Map was declared as <String, Integer>.....
it seems you're doing everything right.
I just want to remind you that, well I'm 95% sure, HashMap and other Collections like it (TreeMap, ArrayList) don't hold primitives... they hold wrapper/boxed classes. That could be the issue why you're getting an "Object" and it expects an "int". You may try casting the int 'number' as an Integer, but autoboxing should take care of that. **shrug**
JD
P.S. If your HashMap is really named hashMap, it's not good naming convention. I dunno if the Nitpickers nitpick that, but I will.