Make plans: present tense (future meaning), numbers 13-31, dates

German numbers 13-19 are simple sums, e.g., 'drei + zehn' = 'dreizehn'. Numbers 21-99 say the second digit first, e.g., 'vierundzwanzig' = '24'. An ordinal number tells you the order of something, e.g. 'first, second, third'. Use ordinal numbers for calendar dates. For 1-19, form ordinal numbers by adding '-te', e.g., 'fünfte'; add '-ste' to 20 and over, e.g., 'einundzwanzigste'. 'Am' means 'on the' and requires an '-n' to be added to the ordinal number, e.g., 'am zweiten März'.