In American Sign Language (ASL), the sign for "more" is commonly taught to beginners and is even used in baby sign language because of its simplicity and usefulness. Here's how to sign "more":

The sign "more" is straightforward and easy to learn, making it one of the first signs introduced in many ASL courses.
Learning to sign is a great start. For the moments that have to be right (a medical appointment, a parent-teacher meeting, a legal conversation) Ava connects you with a credentialed ASL interpreter over video in the Ava app, on demand or scheduled ahead. Available 24/7, with live captions included.