@Axman6 hi, I teach 9-11 year olds and love #maths myself.

Here are some fun and open challenges you could explore :
#OpenMiddle problems - website is packed with examples
#wodb site - open thinking, range of topics
#youcubed
#nrich
#wouldyourather #primeclimb is a great fun board game
#Mathssnacks videos and games
#sudoku
Best wishes, I hope your child stays keen 🤩