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.
I could totally do this with money-- dollars on a pumpkin then popsicle sticks with bills and coins that add up to the amount. Addition/subtraction sorting - child needs to determine which sticks add up to the number on the bucket.