I use magnets in my classes to teach numbers in a fun way. Students have so much fun sticking them on the white board.
They race to put them in order, add and subtract numbers, set the date of the day using them...,etc. These magnets come in different colors and sizes.
One of the activities my students enjoy doing is taking turns demonstrating their skill in putting the numbers 1-10 in order on the board using these magnets everyday before we start our lesson as fast as they can.
You just have to chose what works best for you and your students. You can be so creative with these little magnets. In the world of magnets, EVERYTHING is FUN!