Reading "-" as "Minus"

I am using this app to read some accounting material. For the most part, everything is working out great. One issue that I have is that I need for this app to read some formulas. I have been successful in getting it to read words and symbols the way I want. For example, it now reads the"/" sign as "Divided by" instead of "slash". However, I can't get it to read the minus sign as "minus" instead of skipping it altogether. Can someone tell me if there is anything I can do to make this possible? If I can get it to do this then I will consider it one of the best apps ever written.

Greg,
Your suggestion worked like a charm! It was indeed the type of character that was the problem. When I pasted the minus sign from the formulas, I realized it was actually longer than what I was typing in. Thanks again

Greg, one thing that I wish was there is the page numbers and the ability to jump to a page(Unless I am missing some setting). I have been using ezPDF for a long time and I am trying to use your app as the only pdf reader. The advantage of having the page number especially if it matches the original document is that I can continue to read a copy of my document from where I left using my computer. What do you think about that?