The medieval Cistercian numerals, or "ciphers" in nineteenth-century parlance, were developed by the Cistercian Order in the early thirteenth century at about the time that Hindu-Arabic numerals were introduced to northwestern Europe. They are more compact than Hindu-Arabic or Roman numerals, with a single character able to indicate any integer from 1 to 9999. wikipedia 
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The vertical forms of the digits (1–9, 10–90, 100–900 and 1000–9000), with an innovative form of 5 as engraved on an early-sixteenth-century Norman astrolabe - wikimedia
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Compare Zero is a Dangerous Idea.
See Figuring out: the spread of Hindu-Arabic numerals in the European tradition of practical mathematics (13th-16th centuries) via Economic and Social History at Cambridge working papers site pdf researchgate
These insights about number systems is a metaphor for the scale of educational revolution I have been hoping to see from computing. See Alan Kay's Inspiration.