The numlock have nothing to do with your ability to use the special characters of the number keys.
Can you type UPPER case letters? As your question is all lower casem, it may be related.
If not, it probably means that your shift key is defective.
In that case, there are very probably some other keys that miss function or are about to missfunction.
Most peoples use the shift key on the left of the keyboard. There is another on the right side just under the Enter or Return key. Does that second key works?
Probably time to get a new keyboard.
Electro, April 2011