la clase de matimaticas.
You can say, "There are 23 boys in the math class." Alternatively, you could say, "In the math class, there are 23 boys." Both statements clearly convey the number of boys present in the class.
Voy a empezar las clases..... is how you say i will begin class in spanish
Tengo matemáticas
Tengo la clase de matematicas en la primera hora.
'Clase de tenis' is tennis class in Spanish.
Clase.
You say "prueba de matemáticas".
You say, "Apollo matemático."
Su clase favorita es matemáticas
to say how well you are doing in a class (example below): i am doing good in my spanish class - hago bueno en mi clase española
En el salón hay (The class where I am)
la clase