How do you get the IQ?

Answer 1

IQ tests are standardized for age ranges. You divide the age of the test subject into the 'age' he tested as normal for and multiply by 100 to get IQ. For instance if you are 16 and test as having the knowledge of the average 20 year old then your IQ= (20/16)*100 = 120

Added:

Not only the knowledge of the older person, or younger person, but the abilities shown on the G laden portion of the test, the part of the test monitored by a stopwatch. Such things as reverse span, counting off a series of numbers backwards, mental reaction time, know how old someone is, say, born in 1934, and rotating objects in space, pattern comparison.