一も二も無く[ichimonimonaku] unhesitatingly
一言二言[hitokotofutakoto] a word or two
一石二鳥[issekinichou] killing two birds with one stone
一二に及ばず[ichininioyobazu] right away
一姫二太郎[ichihimenitarou] It's good to have a girl first and then a boy

うり二つ[urifutatsu] as alike as two melons (two peas in a pod)
黄道十二宮[koudoujuunikyuu] twelve signs of the zodiac
二度[futatabi] again
最小二乗法[saishounijouhou] least-squares method
三十二分音符[sanjuunibuonpu] 32nd note

一か八か[ichikabachika] sink or swim
嘘っ八[usoppachi] downright lie
嘘っ八百[usoppappyaku] full of lies
嘘八百[usohappyaku] full of lies
八釜しい[kamabisushii] noisy

口八丁[kuchihacchou] voluble
三十八度線[sanjuuhachidosen] the Thirty-eighth Parallel
四苦八苦[shikuhakku] being in dire distress
四通八達[shitsuuhattatsu] traffic network extending in all directions
四方八方[shihouhappou] in all directions

黄道十二宮[koudoujuunikyuu] twelve signs of the zodiac
丸十[marujuu] cross in a circle
五十音[gojuuon] the Japanese syllabary
五十音順[gojuuonjun] the syllabary order
五十三次[gojuusantsugi] the 53 Toukaidou stages

五十年祭[gojuunensai] jubilee
五十歩百歩[gojuppohyappo] six of one and a half dozen of the other
五十路[isoji] age fifty
三十戸[sanjikko] thirty houses
三十三所[sanjuusansho] any of a number of sets of thirty-three holy places enshrining Avalokitesvara (esp. those comprising a popular pilgrimage in the Kinki region)

安宿[yasuyado] cheap hotel
一宿[isshuku] staying one night
一宿一飯[isshukuippan] (being beholden to someone for a favor of) a night's lodging and a meal
雨宿り[amayadori] taking shelter from rain
下宿[geshuku] boarding

下宿屋[geshukuya] lodging house
下宿人[geshukunin] lodger
下宿料[geshukuryou] board-and-room charge
仮の宿り[karinoyadori] temporary dwelling
寄宿[kishuku] lodging