EDIT This is used in China to represent numbers before numerals appeared.

Back then Chinese mathematican Zhang Heng actually calculated the value of pi using this. Imagine that.
 
EDIT Fonts

Freeware-Fonts, covering all characters of this unicode-block:
Code 2001 or Code 2002 by James Kass
 
U+1D360U+1D361U+1D362U+1D363U+1D364U+1D365U+1D366U+1D367U+1D368U+1D369U+1D36AU+1D36BU+1D36CU+1D36DU+1D36EU+1D36FU+1D370U+1D371U+1D372 NOT ASSIGNEDU+1D373 NOT ASSIGNEDU+1D374 NOT ASSIGNEDU+1D375 NOT ASSIGNEDU+1D376 NOT ASSIGNEDU+1D377 NOT ASSIGNEDU+1D378 NOT ASSIGNEDU+1D379 NOT ASSIGNEDU+1D37A NOT ASSIGNEDU+1D37B NOT ASSIGNEDU+1D37C NOT ASSIGNEDU+1D37D NOT ASSIGNEDU+1D37E NOT ASSIGNEDU+1D37F NOT ASSIGNED
U+1D360 COUNTING ROD UNIT DIGIT ONE
U+1D361 COUNTING ROD UNIT DIGIT TWO
U+1D362 COUNTING ROD UNIT DIGIT THREE
U+1D363 COUNTING ROD UNIT DIGIT FOUR
U+1D364 COUNTING ROD UNIT DIGIT FIVE
U+1D365 COUNTING ROD UNIT DIGIT SIX
U+1D366 COUNTING ROD UNIT DIGIT SEVEN
U+1D367 COUNTING ROD UNIT DIGIT EIGHT
U+1D368 COUNTING ROD UNIT DIGIT NINE
U+1D369 COUNTING ROD TENS DIGIT ONE
U+1D36A COUNTING ROD TENS DIGIT TWO
U+1D36B COUNTING ROD TENS DIGIT THREE
U+1D36C COUNTING ROD TENS DIGIT FOUR
U+1D36D COUNTING ROD TENS DIGIT FIVE
U+1D36E COUNTING ROD TENS DIGIT SIX
U+1D36F COUNTING ROD TENS DIGIT SEVEN
U+1D370 COUNTING ROD TENS DIGIT EIGHT
U+1D371 COUNTING ROD TENS DIGIT NINE
U+1D372 
U+1D373 
U+1D374 
U+1D375 
U+1D376 
U+1D377 
U+1D378 
U+1D379 
U+1D37A 
U+1D37B 
U+1D37C 
U+1D37D 
U+1D37E 
U+1D37F 
CHARACTER  < BLOCK > 
U+1D360 – U+1D37F Counting Rod Numerals
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