In high school, math becomes more abstract. Numbers get replaced by variables. Students struggle at interpreting word problems. Parents cannot make heads or tails of the content. By this stage, many students now have math gaps from earlier years that cause them trouble.
If students are committed to working hard, and if they are not too far behind, the problem can absolutely be remedied. Summer is generally a great time for catch up. Students enter the new school year feeling ready to tackle math class.
Some students can keep up with their classes but feel that they would like extra support while they go through math courses in school. They would like to score higher on tests and achieve better grades than what they are able to do themselves. A lot of my testimonials come from students who were very happy they got an A in math class. They did not think this was possible before.