If you have a Pokemon Egg in your party, and you walk 'X' number of steps then put a Pokemon with Flame Body/Magma Armor is the equation (Y - X)/2=R or (Y/2) - X=R, with 'Y' being the total number of steps needed to hatch the Egg, 'X' being the number of steps taken before putting the Pokemon with Flame Body/Magma Armor in, and 'R' being the remaining steps needed?

That was gonna be the title, but I thought it'd be too long, and didn't wanna try. If you didn't understand that, I can try to dumb it down a little.