why isn't "el nino es un ano" correct?
In Spanish, age is not usually said with the verb "to be". We use "to have" instead. So whereas in English you say "I am 5 years old", in Spanish you say "Yo tengo 5 años (de edad)" = I have five years (of age).
Can you say "El niño tiene uno" or do you always need "año" when talking about ages?