To group columns
To sum by groups in Excel, do these simple steps:
1– Select data, go to ‘Data’ tab and select ‘Subtotal’ option from ‘Outline’ window. (Select data > Date > Subtotal)
2– A ‘Subtotal window’ will open, tick the amount bullet and uncheck all other option below then press OK.
3– Excel will return with the sum of all groups.
To remove subtotals
Select the data tab, and click on ‘Ungroup’ option in ‘Outline’ window. (Select data > Date > Ungroup)
To hide/ show groups
1– To hide, select the negative sign of relevant group or whole.
2– To show, select positive sign of interested group.