The Cat and Bat each count a list of 20 multiples. If the Cat counts in 2s and the Bat counts in 3s, the first number they will both say is 6 (Bat's 2nd and Cat's 3rd). You decide the multiples. The Dog makes a list of Common Multiples. The First in the dog’s list is the LCM. Listing multiples is an easy way to find the LCM. (Try 3 lists).
See https://scratch.mit.edu/projects/279157225 to find the LCM of 3 numbers.
