Learning basic sewing with a polystyrene plate, yarn, + plastic needle. I remember doing this with craft mesh when I was a kid and then graduating to sewing buttons by hand onto little pillows and pockets.
Instead of numbers write the color word on the bottles. Sort pom-poms by color. Empty each bottle and count the pom-poms. Then record how many pom-poms were in each bottle. Add the two colors together for addition practice.