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 (Normal, base-10 with digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9):
Binary (base-2 with digits 0, 1):
Hexadecimal (base-16 with digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F):