Write a check [cheque] 小切手 を書く (cf. Normally, when the first clue is a write-in, i think i am in for an easy time, but not here: 動詞 writing present participle and gerund of write 2016, voa learning english (public domain) what are you doing?
You are writing a lot! As with many pairs of phrasal verbs that contain antonymic particles (such as up and down), write down and write up can nonetheless function as synonyms for some senses.