Original: A "silver dollar" pancake refers to a pancake about 3 inches (7 cm) in diameter - these are usually served in portions of five or ten.
Simplified: A typical portion served in restaurants is 3 to 4 pancakes of more or less 14 cm (5 inch) diameter. A "silver dollar" pancake refers to a pancake about 7 cm (3 inches) in diameter - these are usually served in groups of five or ten.