Yes you can, and the Wechsler Intelligence Scales for Children (also known as the WISC) are widely considered to be the ‘gold standard’ in measuring a child’s intellectual abilities. On the other hand, in most cases, somebody’s intellectual ability cannot be fully summarised by just quoting a single ‘number’.
The Full Scale IQ score (FSIQ) is calculated based on scores from several different subtests, and quoting the FSIQ alone would ignore the fact that the individual child may have particular strengths and weaknesses in different abilities such as their verbal skills, visual-spatial skills, conceptual reasoning, mental manipulation of information, and mental processing speed.
For some children their scores on the various subscales might be quite similar, whereas other children might have strengths and weaknesses that are so dramatically different that the FSIQ by itself is almost meaningless. Understanding this full picture usually helps provide a more in-depth picture and set of recommendations for your child. And of course, looking at the wider factors such as behaviour, self-esteem, and emotional coping will enrich our understanding even further: and addressing these factors may boost academic function as well as overall quality of life.