I'm learning Korean just like you. This is my understanding. The grammar rule is "A/V-(ㄴ/는)다(고) 치다". You attach the adjectives/verbs the same way you would for indirect speech. 1. 가: 수영장에 갈 것입니까? 나: 시간이 없으니까 수영장에 갔다 치고 샤워나 해야겠습니다. 가: Do you want to go to the pool? 나: I don't have the time. I'll just take it that I have been to the pool. I need to at least take a shower. The dialogue didn't make much sense to me. I don't know what "샹워" is, I just assume that it is "샤워". 2. 가: 오늘 저녁에 손님이 몇 명 옵니까? 나: 열 명 정도 온다 치고 식사 준비를 하십시오. 가: How many guests are coming over tonight? 나: Please prepare enough food for 10 persons. (Assume that as many as 10 persons could be coming, please prepare enough food.) "열명" should have spacing in between.

Here 치다 means "to suppose, assume, presume " 다(고) 치다 means "suppose that" e.g. 비행기를 탄다고 쳐도 내일까지는 못 간다 I couldn't get there by tomorrow even if I were to fly[go by plane]. Suppose I go by plane. I wouldn't be able to get there by tomorrow. 그것은 그렇다 치고, 이제 일정에 대해 얘기해 봅시다 OK then[Let's leave it at that]. Now let's talk about the schedule. 수영장에 갔다 치고 샤워나 해야겠습니다. Supposing that I came to swimming pool, I will just take a shower. 열명 정도 온다 치고 식사 준비를 하십시오. Supposing that ten people will come here, prepare a meal, please.