@JonRa
To be fair she's asked him on multiple occasions to help her with math but they haven't actually gotten to studying yet. It's safe to assume from his point of view that math would be her worst subject especially since it's the one she wanted his help on so him asking (albeit bluntly) where her grade or performance stands on the subject would be a good way to ascertain where he really should start if he is to tutor her like she asked.
I thought she was basically an A+ student, good at a lot of things, beautiful and the grandkid of the school owner or some shit. Sure seems like she is getting dumber and dumber