Welcome to 10/10/10: Today is the Answer

Each 0 or 1 in a binary number corresponds to a power of 2 depending on its position. For the number 101010 this means the 0s and 1s correspond to powers of two, from right to left, as follows: 2 to the zero power, 2 to the first power, two to the second power, and so on.

Rendering the binary 101010 into ordinary base 10 notation is as follows, where x^y means x to the yth power:

101010 -> 1 x 2^5 + 0 x 2^4 + 1 x 2^3 + 0 x 2^2 + 1 x 2^1 + 0 x 2^0 = 42,

or

101010 -> 1 x 32 + 0 x 16 + 1 x 8 + 0 x 4 + 1 x 2 + 0 x 1 = 42,

or

101010 -> 42

101010 (base 2) is 42 (base 10).