Quote about difficulties doing multiplication/division prior to Arabic notation On pages 61-62 of Code Complete, 2nd edition, there is this quote about Arabic notation:

By relieving the brain of all unnecessary work, a good notation sets it free to concentrate on more advanced problems, and in effect increases the mental power of the race. Before the introduction of the Arabic notation, multiplication was difficult, and the division even of integers called into play the highest mathematical faculties. Probably nothing in the modern world would have more astonished a Greek mathematician than to learn that ... a huge proportion of the population of Western Europe could perform the operation of division for the largest numbers. This fact would have seemed to him a sheer impossibility.... Our modern power of easy reckoning with decimal fractions is the almost miraculous result of the gradual discovery of a perfect notation.
  —Alfred North Whitehead

My questions are:
What notation(s) prior to Arabic notation is this quote most likely referring to?
Why was it difficult doing multiplication/division using the notation(s) prior to Arabic notation?
How did Arabic notation solve these problems?
 A: Try doing arithmetic in Roman numerals if you want to see why it's so hard. It's a headache. And it was the system of Europe, north Africa, and the Middle East for about 15 centuries.
The Babylonians, long before the "golden age" of ancient Greece, had a perfectly good positional notation, which was lost until archaeological discoveries of the 19th century CE.
See "Roman numerals" and "Babylonian numerals" and "Babylonian arithmetic" in Wikipedia.
I dk whether it was known to Whitehead that what was called "Arabic numerals" in Europe actually  originated in India. And the Chinese and Japanese abaci (singular: abacus) are devices for computing arithmetic in the modern decimal system.   
A: "easy reckoning with decimal fractions": something possible with a positional number representation. With it, it's simple doing arithmetic operations because it's possible to operate figure by figure. However big operands may be, operations on them, even divisions, can always be performed with no particular mathematical faculties. 
The arabic notation is one of the first positional number representation ever. 
