Magnetic number fishing, they add what they catch! As well as addition, develops hand/eye coordination, fine motor--I love this for magnetic letter fishing too! When they catch a letter, they say its name and sound.
Learning, Playing & Crafts for Kids Using Popsicle Sticks
Hide numbers throughout house or yard. Children hunt, find and arrange in order before timer rings. You could use this so many ways - larger numbers, equivalent fractions, rounding.Learn Through Movement - Number Hunt Math Game.
Numicon laminates with tinfoil in the back. Metal detectors to find them in the sand then sort them into the right tin.