Intelligence (IQ) tests are tests of general intellectual abilities. They, measure not a single trait but rather a range of abilities, including memory, vocabulary, verbal fluency, and numerical ability.
Originally, IQ (intelligence quotient) was literally a quotient. The procedure was to divide a child’s mental age (as measured by the intelligence test) by his or her chronological age, and then multiply the results by 100. If an 8-year old child answered questions as a 10 year old might, his or her IQ would be 10 divided by 8, times 100 0r 125