|Image from Montessorialbum.com|
Blue and red number rods:
I made a small set from a photocopy. They are not very hardy. I would definitely make something more sturdy if we were going to use them more often.
A set of printable number rods from Montessori Print Shop
Some people make full sized rods from 1x1s like at Montessori MOMents. There are smaller sized rods like over at Walk Beside Me , but my favorite idea is at Totally Tots . She used the ever present blue and red dupolos. I love it!