I found this a bit confusing, so am offering a translation for non-techies like myself. Copy and paste =MOD(ROW(),2) in Cell C1. Then click on the bottom right corner of that cell. You should see a cross appear. Then click and drag to the bottom row. That will allow you to highlight that entire column down to the bottom entry. The result should be every odd C cell (C1, C3, C5, etc.) will contain a “1” and every even C cell (C2, C4, C6) will contain a “0”.