The Quick Gadgets “Quick Issue Statistics”, “Quick Two Dimensional Filter Statistics”, and “Quick Pie Chart” have advanced functionality which is not available in the Atlassian gadgets, besides being interactive.
Per default the gadgets aggregate the number of issues. In the gadget settings you can edit the “Values shown” to any Jira number field (including custom fields), e.g. Story Points. Changing that you can aggregate e.g. the Original Estimate of all issues which are displayed in the gadget.
Additionally, you can choose the function used to aggregate the field values. Available functions are SUM, AVERAGE, MIN and MAX.