How did simple grouping numeral systems form intermediate numbers?

In simple grouping numeral systems, intermediate numbers are formed through the principle of addition. These systems assign specific symbols to small numbers, a base (such as 10), and the powers of that base (e.g., $b^2,b^3$).1

To represent an intermediate value, each required symbol is repeated as many times as necessary to reach the desired total. For example, in Roman numerals, the number 23 is constructed by repeating the symbol for 10 twice and the symbol for 1 three times, resulting in XXIII. Similarly, early civilizations in the Middle East, such as the Egyptians and Phoenicians, typically repeated unit symbols up to nine and utilized special symbols for tens and higher powers to build larger numbers. This additive approach allowed for the representation of complex values by simply aggregating the values of the individual symbols used.123