Why are 6 and 28 called perfect numbers?

Mia has twice as many quarters as she has dimes If she has 3 dollars and60 cents total how many of each type of coin does she have? Do you need to be good in math to be a aero space engineer? How many toonies will make 1 million? What percent of increase from 16 to 33? What is a synonym for apple? What could be a term in the sequence a equals 3n plus 16 n? What decimal is 1 5? What do you call the numbers in division? 79200 feet equals how many miles? How much should an 10 year old weigh? What number is between 4 and 20? How do you figure out how much room each tile takes for a math problem? 11c equals how many pints? What kind of shape is an eraser? What is the greatest possible error of 54.4 cm? How do you calculate a 2ft long 3ft wide door? How do you divide fractions with a negative fraction? Can be divide without a remainder? How many days old are you if you are 30 years old today? What is the median of 49 62 and 31?