A practical way to use the slot aud figure is to work backwards from what you are willing to spend. Decide the amount for the night, divide it by the number of spins you want, and that is your bet size. If the answer is below the minimum stake on the game, you have chosen a session length the budget cannot cover, and the honest options are fewer spins or no deposit. Volatility is the other half of the calculation, since a high-volatility game can burn through a small balance long before the spin count you planned.
Session length matters more than most players admit. Spin speed and bet size multiply, and a fast tap rate at a larger stake turns a modest evening into a large turnover figure. The reward is the same either way, so stretching the session by betting lower costs nothing in expectation and buys more time on the machine.