The first calculating device is the? By: Sunday|Published on: Jan 20|Categories: Computer Studies WAEC| 0 comments A. Abacus B. Census machine C. Difference engine D. Napier bones. Correct Answer: Option A – Abacus Users Also Read These:Pascal's calculating machine was useful in?An electrical device has 50 turns in its primary…In calculating mean one should?In calculating the national income of a country X,…All but one is not an output device?SEE ALSO A computer program that gathers information about a person or organization without their knowledge or consent is known as?