I want to create a new (third) column in my attribute table. The fields of the new column are supposed to be the summarised value of the two other columns' fields. For example, field 1 of the column I want to create is supposed to have the value 901 (663+238) and so on (see pic)
What function in the field calculator should I use and how do I write the expression?
It mostly seems to summarise the two columns and not the separate fields. I'm not looking to use GROUP STATS or similar, but the field calculator only. I'm working with QGIS 2.18.15 on a Mac.