Math Training Grade 6 With Answer Key and Explanations Purchased at a cram school and used in 2025. I mainly wrote in a notebook. Pencil markings have been erased with an eraser. There are pen markings on a few pages as shown in the images, but I believe it does not affect usability. No name written. This is a used item, so please only purchase if you understand this. Those who are sensitive to such things should refrain from buying.