Well, first of all, in mathematics, the word "of" represents multiplication. Also, when ever a number has the percentage sign(%). It means it is divided by 100.That is, its denominnator is 100. So in this case, 70% is 70/100.
The questions says they won 70% OF the games. That simply means;
70/100×90
When you calculate that, you will get 63. Which means they won 63 of the games. Hope i helped. Have a nice day.
