Count if blank

Hello dears, I have a question regarding counting if the answer is blank, For example.
I have Weekly consumption, some weeks should be blank, I need to create calculation Formulas means if the answer in week 1 is blank, multiply by 6.

Thanks a lot

Welcome to the community, @Almotasem_Ballah! Could you kindly share with the community some dummy questions so that the community should be able to help you out? Please also share with the community the choices and conditions that you would like to have. The more details you provide, the easier it’s for the community to help you.