The prefix and suffix help you define a number as currency, capacity, length, mass, etc. They can be added to values on the chart axis, in labels, and tooltips.
To add a prefix or suffix:
❶ Select the chart.
❷ Open the Data format tab, where you will find the option to enter a prefix and suffix.
❸ Choose to apply the prefix/suffix to the chart axis, to value labels, or to the tooltips.