It can be difficult to see how other number systems (such as binary and hexadecimal) work since they have a different amount of numerals than the ten numerals of decimal. But imagine that you are counting in these number systems using an old-fashioned analog odometer that has a different amount of numerals for each digit.
The following three odometers always show the same number, but they are written out differently in different number systems:
Decimal (Base-10: 0123456789)
Binary (Base-2: 01)
Hexadecimal (Base-16: 0123456789ABCDEF)