Hi, Kristina,
first you should consider, what is a relevance equation.
A relevance equation is a logical term that is either TRUE or FALSE.
E.g. 1+1==2 is TRUE while 1+1=

ist FALSE.
And in your case:
sum(Q1_SQ001.NAOK,Q1_SQ002.NAOK) == 4 is either TRUE or FALSE.
with Q1_SQ001==1 and Q1_SQ002=

it is TRUE, with Q1_SQ001==2 and Q1_SQ002==2 it is TRUE, but with Q1_SQ001==1 and Q1_SQ002==2 it is FALSE
second: These relevance equations are used on group level, question level and subquestion level.
And they are entered in the relevance equation field of this level, either group or question or subquestion.
They are to decide if a group/question/sunquestion is displayed or not.
It is displayed if the equation is TRUE and hidden if the equation is FALSE.
And now you ought to know where the equations are placed.
The first subquestion of your second question has to be displayed if the sum in the first question is greater than 0 (no matter if it is 1 or 3 or 14.)
The second subquestion of your second question has to be displayed if the sum in the first question is greater than 1. You have atleast two ages to enter.
The third subquestion of your second question has to be displayed if the sum in the first question is greater than 2.
And so on.
Joffm