卦算[keisan] paperweight
八卦[hakke] eight trigrams
八卦掌[hakkeshou] eight trigrams palm
本卦帰り[honkegaeri] reaching age of 60
有卦[uke] streak of good luck

六十四卦[rokujuushike] the 64 hexagrams (of the Book of Changes)
卦体糞悪い[kettakusowarui] extremely vexing
卦算冠[keisankanmuri] kanji "kettle lid" radical (radical 8)
卦辞[kaji] commentary (on any of the 64 hexagrams in the Book of Changes)

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