Need to find a behavioral module that incorporates all of the methods used to implement true addition and true subtraction with test bench module

I am looking for a freelancer who can help me find a behavioral module that incorporates all of the methods used to implement true addition and true subtraction with a test bench module. The ideal candidate should have experience in Verilog and be able to work on a project with some design preferences. The test bench module should have a basic level of complexity.