Captfahad, you may be able to get into the training with just the basic math skills, and there are lots and lots of devices available to compensate your shortcomings. Nevertheless, you may want to put some effort into improving your mental calculation skills above the required minimum level, as it will simplify your flying life immensely. Most flying-related tasks require four types of operations, in the order of decreasing importance:
- Exact arithmetic operations - add/subtract, multiply by 2, divide by 2
- Approximate arithmetic operations (with rounding) - multiply, divide
- Approximate simple trigonometry
- Use of Pythagorean theorem
Alternatively, try as many different types of devices as you can find and pick the one you like. I would also strongly recommend asking experienced military pilots for help in choosing one and/or learning the mental tricks, and do so while you are still in Pakistan - I was told your Air Force has a very strong training culture.