03 Numbers
How to form the tens
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The tens are formed from the unit number plus the ending -zig.
The ending -zig begins with -z, therefore the numbers 6 and 7 here again lose the endings -s or -n:
60 = sechzig
70 = siebzig
The number 30 must also be remembered, for it is written with -ß-:
30 = dreißig
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