This is a 1-10 counting activity from on of our fellow Montessori bloggers, Tiffany.
She used 2"x4" labels and backed on cardstock cut to 3"x5". She found clipart that related to the fall and added numbers in 24 pt font (this is the best size for paper clips). You could use clothes pins or any fun clips that relate to your theme. She plans on making them for each of her unit studies.
You might even be able to find theme related clothespins!