Dale's baseball team played 25 games this season and won 20 of them.

what percent of their games did dale's team win?

Here, my friend, is how you find percents (I know because I use them to find my grade on tests all the time):
Take the number you got and the total and write it as a fraction (ex: 2 out of 5 = 2/5)
Now the slash in the fraction is like a division sign. (2/5 = 2 divided by 5)
Now you take the answer (which is prabably a decimal) and multiply by 100 to get you percent.
In this case, you would divide 20 by 25, which equals 0.8, multiply it by 100 and you get 80. the answer is 80%

Yes the slope to this is -5