In decimal each digit represents an amount of increasing powers of ten - units, tens, hundreds, thousands etc.
In binary, each digit represents an amount of increasing powers of two - units, twos, fours, eights, sixteens etc.
(Note, for those that may not know this mathematical fact - any number to the power zero is equal to one. That is why both decimal and binary have units in their first column, without breaking the pattern.
It even continues to work for the digits to the right of the decimal point, with negative powers of ten resulting in tenths, hundredths, etc)
As for yesterday's mathematics:
In decimal each digit represents an amount of increasing powers of ten - units, tens, hundreds, thousands etc.
In binary, each digit represents an amount of increasing powers of two - units, twos, fours, eights, sixteens etc.
(Note, for those that may not know this mathematical fact - any number to the power zero is equal to one. That is why both decimal and binary have units in their first column, without breaking the pattern.
It even continues to work for the digits to the right of the decimal point, with negative powers of ten resulting in tenths, hundredths, etc)