It is not a full sentence but it means: there is a _____ on the wall.
"cuántos cuartos hay en la casa?" means "How many rooms are there in the house" in English.
The litteral translation is - There are students in the class Mexico
It means "What is there in the students desk?"
"Hay que soñar en grande" translates to "One must dream big" in English. It conveys the idea of setting ambitious goals and having big dreams.
This phrase translates to "Are you stupid? There are beans in the house" in English. It is a colloquial expression used to express disbelief or frustration.
"Que hay en tu escuela" in English means "What is in your school?"
how many people are there in your family?
It means "What is there in the big cities?"
A good interpretation would be "What's in class?"
"How many days are there in a year?"
cuantos dias hay en una semana
It means: "How many days are there in this month?"