so remember that percent means parts out of 100 10%=20/100=2/10 Here's a fun restaurant tip remember that 10%=1/10 or just move the decimal place one over to the left 20% is twice of that so 58 10% of 58 is 5.8 20% is twice of 10% of 58 20% is twice of 5.8=11.6 tip is 11.6 then add add that to 58 58+11.6=69.6 cost is $69.6