Finding resistance of a resistor.

As shown in Figure 1, a common resistor usually has 4 color bands, the first two of which indicates the first and second digit of its resistance value while the third band indicates the number of zeros that follows the first two digits.  The fourth band indicates the error or tolerance of the resistor.  For example, the top resistor in Figure has a resistance value of 1 kilo-ohm (10 ohms x 100) +/- 5%. Some resistors have 5 color bands to indicate their resistance values more precisely, an example of which is the bottom resistor of Figure. 
     

  Figure . The color bands of a resistor indicate its resistance value (see Table)

  Table.  Resistor Color Codes