Calc: fix scaled value labels on chart

I created a simple line chart. Data values from 244228 to 508345.

Set Y to start at 0 and go to 550000. Calc initially put Y axis labels 0, 100000, 20000 …

Somewhere in the process of formatting the chart or adding a data series, Calc changed (scaled, truncated?) the Y labels to 0, 10, 20 …

How do I get back the full numbers?

You should check the scale of the y-axis. Double-click on the chart to put it in edit mode, then click on the y-axis to select it, then right-click on it to get the little menu. Select Format Axis, then click on the Scale tab.