Below are labels to fold in half and staple on a snack bag full of either trail mix or M&M's. These can be given as treats to new cub scouts at their orientation, it can be given at a den meeting, on a hike, or at a pack night. If it is on a hike, the entire law can be memorized during the hike. Just pick a treat and keep reciting that line until you get to say... the tall tree leaning sideways, or the mossy rock, or the bridge, etc. Then choose another one. If they like singing, the points fit to the tunes of Macarena or three blind mice.
Learning and memorizing aren't the same. I really like the Trustworthy Tommy song which is on the back of these labels because it uses each point of the law in a simple sentence that can be discussed with even the very youngest scouter. It can explain the meaning of the Scout Law in a basic way that won't be overwhelming to young new boys. I would go over it once before starting to memorize the law.
Memory Aides for Leave No Trace Principles for Kids and Outdoor Code