The first calculating device is the? by Sunday | Jan 20 | 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:An electric device is rated 2000W; 250V. The correct…In calculating mean one should?In calculating the Gross National Product (GNP) by…An electrical device has 50 turns in its primary…Which of the following factors is not considered…