Translation of "40s" in Spanish

This music is from the 40s.

Esta música es de los cuarentas.

Until they were in their 40s, for the first time.

hasta los 40 por primera vez.

Did you know this technology was first developed in the 40s?

¿Sabías que esta tecnología fue inicialmente desarrollada en los 40?

In the '40s, the Federal government passes the National School Lunch Act

En los años 40, el gobierno federal aprueba la Ley Nacional de Almuerzos Escolares

He is in his 40s, a whole new era for America and the world.

Está en los años 40, una era totalmente nueva para Estados Unidos y el mundo.