around 1900–1600 BCE
Babylonian School Multiplication Tablet
Ancient multiplication exercises—with teacher and student errors
Reciprocal and multiplication tables were commonly composed in scribal schools of Sumer and Babylonia. They had relatively standard forms in which student scribes copied an original series of lines multiple times to reinforce "penmanship" as well as mastery and memorization of the facts. This exemplar originated in the ancient Sumerian city of Nippur around 1900–1600 BCE and was reassembled from fragments found by several separate archaeological expeditions.
The front of the tablet contains a teacher's (on the left) and student's (on the right) copy of the 45 times table. The reverse sides contains a list of divisors of 12,960,000 from 1 1/2 to 81 with quotients and a 50 times table written alternately three times. Both scribe's and student's copies contain a number of errors.