Blogger Grid Extended – Multi Column
The default layout for the grid is two columns. If there are more than two columns designated in the Extended options, the number of columns will still automatically align with the width of the container. For instance, if three columns are set, three will display within a container if there is sufficient width.
Gutters or space between columns within the grid can be set in the Design tab within the Sizing options for the Row but, ideally, the Row should only have one column though it’s not required.