Conversely it is theorised that people who are tutored in Maths must be similarly adept with Music. So, Mozart must have been a master of Maths! Joking aside, many parents play Mozart to their babies so that they grow up to be great at Maths.
Actually, the two subjects do harmonise perfectly. It might not seem obvious, but Musical theory is based on Maths. Each note is apportioned a specific place and value that must be counted out as it is played. Similarly, Musical time is presented as a fraction: 3 over 4 for a waltz, and so on. Children who study an instrument work with complicated Maths-based theory every time they play a piece of Music.
When students of Music do Musical theory exercises, they are really doing a Maths paper set to Music. Identifying how many beats go into a bar of Music, for example, is a classic division exercise. They also might have to listen to Music, count along with it, and distinguish its time structure.
Studies show that singing in particular really helps children along with their Maths. It could nurture real confidence, which is often lacking in Maths students.
If you want to encourage your child to improve their Maths, why not consider hiring them a Music tutor as well as a Maths tutor? The two subjects can work wonderfully together.