None of these are entirely correct.
A number is a value assigned to a quantity. For instance, you might see six geese flying north for the summer.
In this case, the "number" of geese is six. It represents a specific quantity of geese.
Pi is also a number, representing the ratio between the circumference and diameter of a circle. It represents a certain quantity (approximately 3.1415927).
A "numeral" is any written symbol which you might use to represent a number or quantity. The figure 6, which you might draw using a pen or pencil, or type on your keyboard or text on your cell phone, is an Arabic numeral.
OK, you may also use VI, the Roman numeral. Or, you may use 6 dots, or 6 slashes. Or you may use the Chinese symbol, or the Mayan symbol. Each of these is a way of representing the number 6, and each of them is a "numeral."