Software testing is an indispensible phase of software development that supports not only productivity but also quality assurance from small to large scale software products. Software Systems essentially need an effective way to develop a strategy for testing various aspects of the system. When we are testing software the first and potentially most critical step is to design test cases. There are many methods which assist test case design. This paper will document the approach known as Equivalence class partitioning. We have partitioned the input into two classes Even and Odd. The proposed approach works for integer inputs only. Partitioning is done on basis of assessment of input conditions that serves as a set of valid as well as invalid set of input values for a test case