First, to estimate we can round 53.82 up to 55.00. Then you can look at it like this: when you divide 100 by 20 you get 5, so 20% is one fifth of 100. Therefore, we want to find one fifth of $55. To do this, you multiply 55*1/5. When you multiply the numerators by each other and the denominators by each other, you get 55/5. When you divide the numerator and denominator by 5, you get 11/1 or $11.
Hope this helps
