original_query: What is positional notation?
query: What is positional notation?
answer: Positional notation, also known as place-value notation or positional numeral system, is a system where the contribution of a digit to the value of a number is determined by both its value and its position within the number.  In contrast to systems like Roman numerals, where each symbol has a fixed value, the value of a digit in a positional system is multiplied by a factor based on its position (e.g., in 555, the three 5s represent five hundreds, five tens, and five units).