I am creating math game application. that generate random number calculation according to use selection

I have 5 Activity.

In activity 1 user needs to select operator(check box) i.e + , - , * and /. In activity 2 user needs to select the range(radio group) i.e. 1-10,11-20,21-30,31-40. In activity 3, seek bar is there. and the value of seek bar is to be adjust according to the range selected in activity 2. if 1-10 is selected seek bar value is to be between 1-10.and user needs to select the number of operations through seek bar i.e between 1-10. In activity 4 , calculation is to be done. e.g if i select + operator and range 1-10 and in seek bar i select 2 then calculation of any number between 1 to 10 for two time should be done. i.e

1+9=10
9+9=18

any random number operation with specific operator .