Buying I want a spesifc simple calulator for WP page

I want a simple calculator to give value to 3-4 variables and make 5 simple calculation results

 

there are free calculator aviliable from wordpress plugin, try this http://wordpress.org/extend/plugins/calculatorpro-calculators/ & its free. have a try

 

Thank you guys. the calculator will be very simple. I tried this plugin and I thought to try to edit it but as I am not familiar I will might spend a lot of time editing or searching that's why I asked if someone who is familiar can do it with a low budget.

 

as people ask me details.
I just want to take 3 integer inputs -let's say a,b,c
and calculate and print results
r1 = a*b/240
r2 = a*c/237,5
r3 = a*(b +c)/12,5
r4 = min(a/2, r3)

that's all and I don't mind if it is php or java.

Bugdet is about 10 - 30 $ If it more difficult as it seems I will just buy a plugin that costs 97$

Thanks guys