Mathematics for me was one of the if not the most toughest subjects to learn when I was younger the highest level I got to was Fractions I believe it starts from bottom to highest to Addition, Subtraction, Multiplication, Division, Fractions, Decimals, Percentages, Algebra, Geometry, and Calculus. Although you have plenty of Graph's, Money Solving, and Clock solving ones too that kinda mix things up about with different numbering types.