To sign same, curve your index, middle and ring fingers in and extend your thumb and pinkie, pointing in opposite directions. Move your dominant hand back and forth, creating an arc, while each finger points to the objects that are equal. For example, if you want to say "same as you", the thumb would point to the person signing and the pinkie would point to the other person.
We use signs like same and different to teach our babies to contrast objects and people. This sign is best learned by using two equal objects.
Use the same flash card when we are ready to teach our babies contrasts and similarities. We used blocks of the same shape and color to introduce the idea of sameness.