Step 1:  Using the keypad, create a mathematical equation to power the railgun.
    
    
    Step 2:  The result should be less than or equal to the health of the asteroid.
    
    
    Step 3:  Click on the firing button to launch a projectile toward the asteroid.
    
    
    Step 4:  If the result is more than the current health of the asteroid, the railgun will overload, damaging you.