To sign bowling, take your open 5 hand, face it downward to your side, then extend your middle finger and thumb as if you are grasping the respective holes of a bowling ball. Finally, pivot this hand back and forth, as if you are getting ready to bowl!
Teach your child the bowling sign in the context of watching an actual game, whether on screen or live. It would be great to have a toy set of mini bowling pins and a ball at home, so that your toddler can explore this "sport" and see if they'd like to play it often.
This is a useful flash card taught best in conjunction with other sports or toy flash cards. Toddlers usually like to copy what their parents do, whether it is sports, household chores, or errands. Buy your toddler a mini-bowling set to have fun with at home.