Scientists believe that intelligence can be measured or tested. A type of intelligence test would be solving many problems in a very short time. Most of the problems have to do with seeing things, or telling what a rotated shape would look like. Some are also related to mathematics: for example to tell what number would come next in a row. Other tests have to do with words or the understanding of language. After giving such a test to a person, a number would be calculated to give an approximation of the Intelligence Quotient (IQ).