What you need:
Colored fabric (two to five colors works)
A tally mark silhouette
Heat'n Bond or some other iron-on adhesive
1. Trace your tally mark onto the smooth side of the iron-on adhesive paper.
2. Iron the adhesive onto your colored fabric, marking sure to divide the number of tallys per color that you desire.
3. Cut those tallys out like crazy.
4. Arrange in the pattern of your choice on the shirt. Iron.
5. Let your kid be the rock star of the 100th day of kindergarten.