IQ means Intelligence Quotient. Intelligence is our capacity to know, learn and understand any particular thing like words, calculations, shapes, problems, capacity for rational, logical and analytical thinking and memory. Quotient means a ratio shown as how high or low it is in comparison to 100. 100 means normal. More than 100 more than normal and less than 100 less than normal.
Now let us see how it is calculated.
Let us assume this for the sake of understanding:
A child of 6 years can add single digit numbers and a 8 year old can add double digit numbers.Now my child who is six years can add double digits. So the math IQ is determined to be
(Mental Age ÷ Chronological Age) x 100
Here (8/6)*100 = 133.33
The formula was: IQ = Mental age ÷ Physical age × 100.
No matter what the child's chronological age, if the mental age is the same as the chronological age, then the IQ would equal 100. Modern intelligence tests, such as the current Stanford-Binet test, no longer compute the IQ using that formula. Source : Wikipedia
