As in English, German has special words for the numbers 0 to 12 and then begins a pattern at thirteen. Zero through 12 in German are: null, eins, zwei, drei, vier, fünf, sechs, sieben, acht, neun, zehn, elf and zwölf.
German's blank-teen pattern begins at thirteen. Numbers 13 to 19 in German are: dreizehn, vierzehn, fünfzehn, sechzehn (not sechszehn), siebzehn (not siebenzehn), achtzehn and neunzehn.
The "-ty" pattern of tens in English is represented by "-zig" in German. The only exception is thirty, which ends in "-ßig". Twenty through 100 by tens in German is: zwanzig, dreißig, vierzig, fünfzig, sechzig, siebzig, achtzig and neunzig.
German creates numbers after 21 in a different way than English. The numbers are inverted, linked by the word "und" ("and"), and written as one word. Twenty-one to 25 in German are: einundzwanzig, zweiundzwanzig, dreiundzwanzig, vierundzwanzig and fünfundzwanzig. This pattern works for numbers 21 to 99 and in larger numbers that end this way.
Counting by hundreds in German, from 100 to 1000, is straight-forward: hundert, zweihundert, dreihundert, vierhundert, fünfhundert, sechshundert, siebenhundert, achthundert, neunhundert and tausend. Counting in thousands works the same way as the hundreds. One million in German is eine Million, one billion is eine Milliarde, and one trillion is eine Billion. (Note both the capitalization and the differences between the two languages in vocabulary.) Compound German numbers are written as one word, which can lead to long, tongue-twister words like fünfhundertfünfundfünfzig (555).