Feeling or believing

EN: According to best practices baby considered content after 3 Oz of liquid food. Easy to say! How would you explain it to crying baby?
RU: Soglasno rekomendatsiyam po uhodu za det'mi rebenok schitaetsya sitim posle upotrebleniya 84 ml zhidkosti. Horosho skazat'! Kak bi eto obiyasnit' plachuschemu rebenku?