bin  hex
---- ---
0000 0
0001 1
0010 2
0011 3
0100 4
0101 5
0110 6
0111 7
1000 8
1001 9
1010 A (10)
1011 B (11)
1100 C (12)
1101 D (13)
1110 E (14)
1111 F (15)

  11011000
= 1101 1000
= D 8
= 0xD8

  (1 << 6)
  00000001 (1)
  01000000 (1 << 6) - the above shifted 6 places to the left
= 0100 0000
= 4 0
= 0x40