Ratios are a fancy way of saying chance, here’s an example:
I have 1 six sided dice and I need a six to win the tournament. What is my chance in winning or losing if I need to get a six with the dice?
The chance of me getting a six is a one in six chance because there are six numbers on the dice and there is one six, so that is 1 in 6 chance that I will roll any number from 1-6. ⅙ is the fraction or 16.5%
You would use probability in gambling, and also insurance like say when you have had your full driver's licence for 10-15 year then the probability of you crashing is about 20%-30% that you won't crash because you have had your driver's licence for a longer time. If you have had your licence for 1 year, so if that is the case then you would have a 40-50% chance of crashing which means that you will have less insurance cover. So that is the explanation of probability and remember maths is everywhere.
Another way to do some maths with probability is transfer decimals( 0.25) into a fraction and a percentage which would be ¼ as a fraction and 25% is the percentage.