As in English, there are two types of numbers in Russian: the CARDINAL (or counting) numbers and the ORDINAL (or descriptive) numbers. Examples of cardinal numbers are:
один, два, три, десять, двадцать, сто, тысяча, миллион
Examples of ordinal numbers are:
первый, второй, третий, десятый, двадцатый, сотый, тысячный, миллионный
The ordinal numbers are actually adjectives which answer the questions какой? какая? какое? какие? Remember these from Lesson 2? Therefore, they'll behave just as any adjective does, agreeing with the nouns they modify in GENDER, NUMBER AND CASE.
In this lesson, you saw the expressions на первое, на второе where there were only ordinal numbers (in the neuter) and no noun. The understood noun in these instances was блюдо. So, первое блюдо means first course, второе блюдо means second course.
You will also use the ordinal numbers to indicate the date:
Сегодня десятое (число-understood, not expressed) апреля.
Here are a few ordinal numbers and their corresponding cardinal forms. The ordinals are given in the masculine.
первый | один |
второй | два |
третий | три |
четвёртый | четыре |
пятый | пять |
шестой | шесть |
седьмой | семь |
восьмой | восемь |
девятый | девять |
десятый | десять |
двадцатый | двадцать |
двадцать первый | двадцать один |
двадцать второй | двадцать два |
тридцатый | тридцать |
сороковой | сорок |
пятидесятый | пятьдесят |
сотый | сто |
тысячный | тысяча |
миллионный | миллион |
Go back through Lessons 1-7 and find examples of ordinal numbers. Explain how they were used and with your instructor's help, try to use them yourself.