At that age my son loved the Penrose books, bedtime math books, and Beast Academy guidebooks as far as stuff to read and think about goes. We focused more on logic than math in our homeschool because he was a few years ahead just learning through play (and he loves math, so much much of his play revolved around math). Some of the logic stuff DS enjoyed included: Laser Maze, mazes in general, board games/card games/chess, and Sudoku. One of his favorite games at that age was Prime Climb. He went through a phase where he loved to graph equations and we did that for a while for math. I also had him do word problems at the level he was able to do calculations at, so about 3rd/4th grade level. This was challenging for him without further advancing his formal math instruction and a very useful skill for school and life.
A current favorite is a puzzle book called Pinwheel Paintdoku and his favorite game right now is Mancala (which I've only managed to beat him at once) and his favorite electronic toy is his lights out cube. Since DS is in school again we just have fun and play board games at home and I really think that teaches a lot of skills/math/logic.
