What does "How much should I add?" mean in English for Spanish?

In English for Spanish, "How much should I add?" means:

¿Cuánto debería añadir?

Listen to "How much should I add?": (If you have an HTML5 enabled browser, you can listen to the native audio below)

This is a phrase that is used in the GamesForLanguage English for Spanish Language Game in the following scenes:

• English for Spanish 3, Level 3, Scene 3