Is this to be understood only in the context? Assuming the と is conditional
The と is not conditional, and you can tell that from the word followed by the と.
The conditional と should follow 活用語の終止形/the terminal form of a conjugatable word, such as verb, i/na-adjective, auxiliary, eg 「話す」「寒い」「静かだ」「〇〇だ」「~ない」. It cannot follow a 体言(unconjugatable word).
Eg.
食べると太ってしまう
明るいと眠れない
静かだと勉強がはかどる
佐藤さんがいないと困る
When と is attached to a 体言 (unconjugatable word) as in your example where と is attached to 「10」, it should be the case particle (格助詞).
The case particle と can attach to words of various part-of-speech (because of its quotative usage). It can be used for saying "~ and ~" (enumeration), "with (someone)", (same/different) as/from..." (comparison), "(saying) that..."(quotation), etc., as you probably know.
Eg.
13と14 -- "~ and ~" ← と follows 体言
リンゴとバナナとヨーグルト -- "~ and ~" ← と follows 体言
妹と一緒に勉強する -- "with (someone)" ← と follows 体言
山田さんと同じクラス -- "(same) as ~" ← と follows 体言
いやだと言う -- "(say) that..." ← と can follow various words
And as you can see, と in the sense "~ and ~" would make the most sense in your example.
"14は10といくつ?"
I'd say the は is the topic marker, or the thematic は (主題の「は」).
lit. As for 14, 10 and how many (is it)?