Use colored dots to make groups easy. Put a different colored dot on each desk in a group. When you need to have a student from each table do something, you can simply ask for all the green dots to bring you the papers from their group. << or put dots on back of hands for any group activities. also, could assign random colors each day to each child and to ask questions, you have a container with the matching colors - or a spinner - and you call a color.
Teacher: "Why do I hear people talking? Me in my head: "Because the sound waves of our voices travel through the air until it hits you let eardrum and causes it to vibrate, so you can hear the wonderful and intelligent things coming out of our mouths :)"