Research has shown there are two things that make people good at math and they have nothing to with academic skill.
One is recognition and the other is interest. This study confirmed it. http://phys.org/news/2015-06-math-person-recognition-key-factors.html
Making math interesting can be done by making it engaging. Make math part of a project or another activity. Explain and describe the practical use of it.
Recognition of when a skill has been mastered or an idea grasped is equally if not more so. Recognising good work boasts confidence and inspires people to learn more and to keep playing and learning the subjects.
The same article gives a few good ideas inspire children to learn through the summer vacation. Check them o