Casio fx-991ES PLUS scientific calculator

The Casio fx-991ES PLUS is a highly popular scientific calculator designed for students and professionals. The brand Casio has its roots in Japan, founded shortly after World War II by the Kashio brothers. It is well-known for pioneering electronic calculators and digital watches. While the brand is quintessentially Japanese, manufacturing for high-volume consumer electronics like the fx-991ES series has largely shifted from Japan to large-scale facilities in China, Thailand, and Vietnam to optimize global distribution.

Today, the brand remains under the ownership of Casio Computer Co., Ltd., which is headquartered in Tokyo, Japan. The company continues to lead in the educational technology sector, providing specialized calculators tailored to various national curricula around the world.