I found the cute little rhyme for 10 Little Dump Trucks on a previous Flannel Friday at YA Librarian Tales from 2012.
I found cute dump truck clipart with a Google search (this is the exact one that I used).
I changed this rhyme up because my storytime attendance number varies. Instead of saying each child's name, I substituted with the color of the dump truck, but I let the kids decide what each truck was filled with.