Breakdown of Мы говорили о количестве: нам нужно около пятидесяти калькуляторов.
мы
we
говорить
to speak, to talk
о
about (о, об, обо)
нужно
it is necessary
Questions & Answers about Мы говорили о количестве: нам нужно около пятидесяти калькуляторов.
Why is the number fifty written as пятидесяти here?
The preposition около (meaning "about" or "around") requires the Genitive case. When declining compound numbers like пятьдесят (50), both halves of the word change. Both пять and десят decline like nouns ending in a soft sign, taking the ending -и in the Genitive. Fused together, they become пятидесяти.
Why is калькуляторов in the Genitive plural?
Numbers from 5 onwards require the following noun to be in the Genitive plural when the phrase is in the Nominative or Accusative case. Here, the preposition около forces the entire phrase into the Genitive case. Since the Genitive case of a plural count (calculators) is the Genitive plural (калькуляторов), the form matches.
Why use нам нужно to say "we need"?
The standard Russian structure for "need" uses the Dative case for the person needing something (нам - to us). The word нужно is a short-form adjective. Because the "thing needed" in this sentence is a numeric phrase rather than a single Nominative noun, нужно takes its default neuter form.
Why does количестве end in -е?