Why are there so many different forms of "the" in German?

All nouns in German have a 'case' and this means that a different form of the noun is used depending on what its role is in the sentence. For example, if it is the subject (the 'do-er' of the action) or the object (the thing having the action done to it). In German, there are four 'cases' - nominative, accusative, genitive, dative. The case is shown by the changing of the 'definite article' which is the fancy term for "the".BUT since German nouns also have different genders (masculine, feminine or neuter) as well as singular and plural, there are four variations on the word "the" ("der") for each case. This sounds super complicated but don't worry, when you look at it in a table, it makes much more sense. [I would then draw the table of cases on the screen and say them out loud to the rhythm which is easy to remember. I would encourage the student to repeat this several times and then encourage them to attempt to write down the table from memory].