Information Representation
Binary - Binary to Decimal a summary:

1. Create a binary weighting table.

2.Look at each bit in the number and, if it is a 1, then write its bit weighting in a list.

3.Add the values in the list to calculate the decimal number.

Example:
128 64 32 16 8 4 2 1
1 0 0 0 1 0 1 0

Hence: 128 + 8 + 2 = 138