Given you have a fair coin, probability of H or T is 50%. You will see the probability equal closer to. 50 as the number of clips increase (law of big numbers) . The key to solving this problem is to look at the binomial distribution with a probability of success equals 0.50 and failure 0.50. The should be many calculators to examinne when the probability should convert to 0.5. You can also add cofindence interval (99% CI). There is a formula to do all of but I would start off by playing around with an online calculator or you can try to use MS Excel, which most people have access to. Let us know how you are proceeding, since we are happy to help.