When parents want to have the intelligence of their child determined, often it’s because the child appears to have a very low or a very high intelligence. For all other cases, the regular school exams and progress tests will usually suffice.
As an IQ test for children is only necessary in special circumstances, the interests of the persons involved tend to be larger. Does the child require special education? Is the child highly gifted and is remedial teaching needed? This type of findings can have far-reaching consequences.
Of course there are easier ways to get to a better understanding of a child’s intelligence than taking a comprehensive IQ test for children. You can try to asses how easily (and quickly) a child solves logical problems or perceives similarities between different situations. This can provide strong indications, even though it is not standardized and objective.