The math is still there and it's even easier to calculate! For example the article states that the house keeps $0.07129 for every dollar spent, or put another

The math is still there and it's even easier to calculate! For example the article states that the house keeps $0.07129 for every dollar spent, or put another way, for every $100 coming in, the machines need to pay out ~$93. Therefore, you can expect to lose on average $7 for every $100 you spend on slots.