This didn't really state what you wanted to find. But I'm assuming you're trying to find how much of the 60 cans she sold if you collected 81%.
In this case your equation would be 81% of 60.
The first thing you do is convert 81% to a decimal by moving the decimal place 2 spaces to the left. So you get .81 of 60
"of" states multiplication, so .81 times 60 is 48.6
So Maggie collected 48.6 cans out of 60
