Download or read book Imaginary Abacus - Instruction Book written by Paul Green and published by Createspace Independent Publishing Platform. This book was released on 2017-10-15 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Learn to add and subtract in your head by imagining an abacus to calculate the result. Example: Learn to calculate 415-350+233-155+44 quickly, just by imagining an abacus.This book will teach you the skills required to firstly use the actual abacus effectively, then how to use an imaginary abacus (also known as a mental abacus). To follow this book you will need: 1) A Japanese abacus (with at least 13 columns). 2) The accompanying workbook 'Imaginary Abacus - Workbook' (sold separately). This useful and impressive skill would be an asset for anyone.