Basic Binary Knowledge

There is a basic knowledge that I think everyone must have in mind: Basic Binary Numbers. So, let's get to the point:

Decimal and Binary (4 bits)

0 = 0000

1 = 0001

2 = 0010

3 = 0011

4 = 0100

5 = 0101

6 = 0110

7 = 0111

8 = 1000

9 = 1001 (nice binary palindrome! Try 73)

HIT: See how even numbers ends with 0 and odd numbers with 1.