In order to win the Lottery you must pick the right six numbers out of 50 potential balls. The order in which you pick the numbers does not matter, but they have to be the same numbers that come out of the Lottery machine.
The odds of you choosing a correct number all depends on how many balls you’ve already chosen. For example, when the lotto draw starts and you’ve already got one number right and there is a total of 50 numbers to choose from and six balls are about to be picked, you have six tries in total to land the correct numbers. This equals to the odds being of you picking one correct number only 50/6=8.3%.
You can use a similar calculation to determine your odds of picking another correct number, so there are 49 lottery balls left and five more balls to go, therefore the odds of you picking another correct number is 49/5=9.8%.
In some countries they increase or decrease the number of balls to change the odds of you getting the correct numbers. Large jackpots often lead to more ticket sales, if the prize is not large enough then they’d decrease the ticket sales. If the odds of you winning is too low then ticket sales would also decline, so it’s important for each lottery to have a balance to keep people playing.