As an example of significant figures, suppose that we are asked in a laboratory ex- periment to measure the area of a computer disk label using a meter stick as a measur- ing instrument. Let us assume that the accuracy to which we can measure the length of the label is * 0.1 cm. If the length is measured to be 5.5 cm, we can claim only that its length lies somewhere between 5.4 cm and 5.6 cm. In this case, we say that the mea- sured value has two significant figures. Note that the significant figures include the first estimated digit. Likewise, if the label’s width is measured to be 6.4 cm, the actual value lies between 6.3 cm and 6.5 cm. Thus we could write the measured values as (5.5 * 0.1) cm and (6.4 * 0.1) cm