Long and short scales
two of several different large-number naming systems for integer powers of ten / From Wikipedia, the free encyclopedia
The long and short scales are two of several large-number naming systems for integer powers of ten that use the same words with different meanings. The long scale is based on powers of one million (1,000,000), whereas the short scale is based on powers of one thousand (1,000).
For whole numbers less than a thousand million (< 109), the two scales are the same. From a thousand million up (≥ 109), the two scales differ ever more, using the same words for different numbers, which can cause misunderstanding.