The Sumerians ' abacus consisted of a table of successive columns which delimited the successive orders of magnitude of their sexagesimal number system .
The earliest known tool for use in computation was the abacus , developed in the period between 2700 -- 2300 BCE in Sumer .
The Sumer ' abacus consisted of a table of successive columns which delimited the successive orders of magnitude of Sumer 's sexagesimal number system .
The earliest known tool for use in computation was the abacus , developed in the period between 2700 -- 2300 BCE in Sumer .