Hi @aanikue,
You are looking for the “Apply to grouped entries” rounding feature that is currently only available in Analytics (not the Reports). When you create a table chart, there’s going to be a little gear at the top right, giving you rounding options.
However, are you subscribed as a Beta user? In the coming weeks, we are rolling out a new Beta version of reports, and you will be able to see this grouped rounding option in the Summary or Detailed reports 