In pediatric clinics, after a child has been tested for intelligence, we often encounter parents who ask, “How many points did my child get? It is true that intelligence tests, like height and weight measurements, have a standard for evaluation, which is called IQ. IQ is short for intelligence quotient. IQ was originally based on the concept of mental age, which was originally expressed as IQ age. In an IQ test, a 6-year-old child is 6 years old if he or she can complete the items in the 6-year-old age group. Later, it was found that there were many problems with the calculation of IQ age, and it was thought that IQ age could not directly reflect the different levels of intelligence in the actual age, so it was proposed to use IQ to assess, that is, the ratio of IQ age to actual age. For example, the child above, whose actual age is 6 years old and whose IQ is also 6 years old, has an IQ = 6 years old/6 years old x 100 = 100; if a 5-year-old child, whose measured IQ is 7 years old, has an IQ = 7 years old/5 years old x 100 = 140; and another child, who is also 5 years old, whose measured IQ is 3 years old, has an IQ = 3 years old/ 5 years old x 100 = 600 So what IQ is considered normal? The normal IQ range is 70-130, with an average of 100, which means that if a child’s IQ is above 130, he or she has excellent intelligence, 120-129 is excellent, 110-119 is smart, 90-109 is moderate, 80-89 is low, and 70-79 is critical. If a child’s IQ is below 70 and is accompanied by low social adaptability, he or she can be considered mentally retarded and should go to the hospital for further examination. There are also levels of intellectual backwardness, with IQs of 55-69 being mildly backward, 40-54 being moderately backward, and 40 or less being severely backward.