逆算

Reading

Kana: ぎゃくさん

Romaji: gyakusan

Definitions

noun

vs

1

counting backwards; calculating backwards

noun

2

inverse operation; reverse operation

Kanji

逆

Readings: ギャク、 ゲキ、 さか、 さか.さ、 さか.らう

Meanings: inverted, reverse, opposite, wicked

算

Readings: サン、 そろ

Meanings: calculate, divining, number, abacus, probability