Binary

8-bit:

64 32 16 8 4 2 1

1 1 1 1 1 1 1 1
=64+32+16+8+4+2+1
=127

1 0 0 0 0 0 0 1
=64+1
=65

0 0 0 0 0 1 1 1
=4+2+1
=7

0 0 0 0 0 0 0 1
=1

There are 10 kinds of people in the world: those who understand binary, and those who don't.