How to put a constraint in the second question based in an input from the first question?

[Kal_Lam]

Have you gone through our support article Limiting Responses with Validation Criteria? It should solve your issue.

As a workaround, this post discussed previously should be helpful for you:

How to validate the female and male entries with the total entry

Hi @Sylvain_DOAMBA, Simply expanding what @stephanealoo has advised. In the survey tab of your xlsform: [Image 1] Data entry screen as seen in Enketo: (wrong entry) [Image 2] Data entry screen as seen in Enketo: (wrong entry) [Image 3] Data entry screen as seen in Enketo: (correct entry) [Image 4] Reference xlsform: Calculation.xlsx (9.1 KB) Have a great day!