An electronic pocket calculator; a small electronic device for arithmetic used in school or work. Often abbreviated as 'dentaku'.
数学の授業で電卓を使ってもいいと言われた。
We were told we could use calculators in math class.
電卓の使い方を忘れてしまったので、スマホの電卓アプリを使った。
I forgot how to use my calculator, so I used the calculator app on my phone.
この電卓はメモリー機能が付いている。
This calculator has a memory function.