why is doing pencil and paper computations not doing mathematics

http://tyachiv-rda.gov.ua/user/f4tqgmx472/

Methods to Develop Excellent Mathematic Students <h1>Methods to Develop Excellent Mathematic Students</h1> <p><img src="https://cdn.stocksnap.io/img-thumbs/960w/L2ZWQVVJED.jpg" style='clear:both; float:right;