Dahl's story "Matilda" revolves around the character of the same name. Matilda's brilliance is overlooked by her parents who appear to think she is annoying.
The family includes a son, Matilda's older, ten-year old brother, Michael, or Mike. Michael is not a genius like Matilda but is just an ordinary boy with no special abilities such as Matilda has. However, her parents find Matilda's genius and habits to be quite annoying. As such is the case, her parents favor Mike over Matilda's genius.
Michael takes after his father but appears to be somewhat less intelligent. Though one could not classify Michael as often kind to his sister Matilda, he is not mean to her and tolerates her better than his parents do. Michael
His name is Michael. He is five years older than Matilda, who is five for most of the story. The two of them really don't do much together because they are so far apart in age.