Noah did a great job sorting these first by number (all the 1s together, all the 2s together, etc). The fact they were also coded by color helped him achieve success the first time. Once he had them in the right stacks, I pointed out the numbers on each Duplos and used the word same (“One, one, one. These are all the same”).
Next, I had him make stacks with the 1, 2 and 3. Again, since he already knows his colors, the fact that these are color-coded provided a great foundation to “build” his new counting skill upon. Incidentally, this activity is a good example of sequence being a pre-math skill. First a child learns to sequence colors, blue, yellow, green; later they sequence numbers, 1, 2, 3.
I love, love, love being able to make teaching materials out of things I already have! I think the materials being familiar to Noah (5-Down syndrome) give him that little extra confidence that helps his willingness in trying a new skill. And, gee, we need all the help we can get.