How to make 0 a default value before select yes = 10 and no = 5

[wroos]

Hello @ma_cabealawa,
You can use a cascading if:
if( … = ‘yes’, 10, if( … = ‘no’, 5, 0) ).

Side-note: Why do you want to set 0. If it is for the sum calculation, you could use the coalesce function
see ODK XForms Specification