Page:Smith - Number Stories of Long ago (1919).djvu/83

NUMBER STORIES use the suan pan, and the Japanese use the soroban. Even in Europe and America our most important computation is done by machinery, our banks all using adding machines, and our large corporations using machines for multiplying and dividing. Workmen in shops of various kinds often use a slide rule. Probably all of you have seen such an instrument, and some of you may have learned how to multiply by sliding part of it along to the right or left.

Number Stories, p60-illustration.png PART OF A SLIDE RULE Such slide rules are extensively used in many industries to-day

This shows how Caius and Wu and Robert and many other boys in various parts of the world met the difficulties arising from poor numeral systems and overcame these difficulties by machinery, and how we are to-day coming to use machinery to help us in our work with numbers, especially in banks and workshops. 60