Each child creates a character with fun aspects like Race: Orc, Profession: Alchemist or whatever.
Their character then gains experience points and skill points in various classes like Maths, English, etc. on completion of classwork, coursework, homework. Rather than being given a B+, the kids would
get: History +5, English +2, Handwriting + 1, spelling +1.
They could also have special abilities like High Jump or Carpentry.
Each year they level up.
This would make it easy to see an ongoing progress chart without formal test taking. It would also encourage kids to work on their weak points in a fun way, by having optional themed quests/missions that they could take.
It doesn't have to be D&D themed, it could be like Hogwarts or something else, but not Pokemon.