Author: Jason Wang
Date: Nov 10th, 2015
Version: 1.0
Functionality: Simple Calulator
1. Implementation of basic arithmatic (plus/mius/mutiply/division)
2. By now just can be operated between two operands
Bugs:
1. Precision Problem
2. Some kind of things I have not realized
Future work:
1. Implement the operation of multiple operands
2. Add more operators to do more complicated arithmatic