Multiplication—the mathematical operation of multiplying numbers; used from elementary arithmetic to advanced mathematics (e.g., matrix multiplication).
小学校ではまず乗算（掛け算）を学ぶ。
In elementary school, students first learn multiplication.
行列の乗算は一般に可換ではない。
Matrix multiplication is generally noncommutative.
プログラムで大量の乗算を行うときは処理時間に注意する。
When performing many multiplications in a program, pay attention to processing time.