This document discusses number bases and converting between different number bases. It provides examples of representing the number 23 in bases 8, 9, 10 and converting between bases such as binary, octal, hexadecimal and decimal. It explains that the base number tells us the size of places in a positional number system. Examples are given of dividing numbers and tracking remainders to convert between bases like base 10 to base 5 or base 6.