We used to play alternate counting games with different bases. Ten replaces the base number. So, counting in base five is one, two, three, four, ten, eleven, twelve, thirteen, fourteen, twenty. In base two, binary, it is one, ten, eleven, one hundred, one hundred and one, one hundred and eleven, etc. Tranlating to decimal you count the number of numbers you said, so in base five above twenty is ten, and in base 2 one hundred and eleven is seven.