"Can you hold your yell until we get outside? I can't hear you with all these people around."
"The tantrum place is in aisle 7 and we're in aisle 5. You can't scream here, silly. Let's sing the alphabet while we walk there..."
"Put your scream in your hand until we get to the car. Don't open your fist! It'll get out. No peeking. Don't let anyone see your hand!"
"Hey, can you hold my keys (purse, cell phone, sunglasses, anything exciting) while I finish up?"
"When I'm mad, I get hungry. Let's go on a treasure hunt for some food and a drink."
"Oh, no. Anyone yelling here gets flipped over Momm''s back and spun around. Watch out...here I come!!"
When all else fails: "I think your patience has run out. Let's go home."