血清[kessei] serum
粛清[shukusei] (political) purge
真清水[mashimizu] pure water
清ます[sumasu] to clear
清む[sumu] to clear (e.g. weather)

清い[kiyoi] clear
清まる[kiyomaru] to be purified
清め[kiyome] purification
清める[kiyomeru] to purify
清らか[kiyoraka] clean

アナログ計算機[anarogukeisanki] analog computer
シフト演算機構[shifutoenzankikou] shift arithmetic unit
暗算[anzan] mental arithmetic
違算[isan] miscalculation
一般命令演算機構[ippanmeireienzankikou] general instruction unit (computer)

運算[unzan] mathematical operation
演算[enzan] (mathematical) operation
演算機[enzanki] processor (as in computer chip)
演算子[enzanshi] operator
演算手順[enzantejun] algorithm