Editing Indus Valley Civilisation (section)

=== Metrology ===
[[File:Harappan (Indus Valley) Balance & Weights.jpg|thumb|upright=0.9|Harappan weights found in the Indus Valley, ([[National Museum, New Delhi]])<ref>{{cite book |title=Art of the First Cities: The Third Millennium B.C. from the Mediterranean to the Indus |date=2003 |publisher=Metropolitan Museum of Art |isbn=9781588390431 |pages=[https://archive.org/details/artoffirstcities0000unse/page/401 401]–402 |url=https://archive.org/details/artoffirstcities0000unse |url-access=registration}}</ref>]]

{{further|Indian mathematics#Prehistory}}
The people of the Indus civilisation achieved great accuracy in measuring length, mass, and time. They were among the first to develop a system of uniform weights and measures.{{dubious|date=June 2019}} A comparison of available objects indicates large scale variation across the Indus territories. Their smallest division, which is marked on an ivory scale found in [[Lothal]] in Gujarat, was approximately 1.704&nbsp;mm, the smallest division ever recorded on a scale of the [[Bronze Age]].{{citation needed|date=June 2019}} Harappan engineers followed the decimal division of measurement for all practical purposes, including the measurement of mass as revealed by their [[hexahedron]] weights.{{citation needed|date=June 2019}}

These [[chert]] weights were in a ratio of 5:2:1 with weights of 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, and 500&nbsp;units, with each unit weighing approximately 28&nbsp;grams, similar to the English [[Imperial units#Mass and weight|Imperial ounce]] or Greek uncia, and smaller objects were weighed in similar ratios with the units of 0.871&nbsp;. However, as in other cultures, actual weights were not uniform throughout the area. The weights and measures later used in [[Kautilya]]'s ''[[Arthashastra]]'' (4th&nbsp;century BCE) are the same as those used in [[Lothal]].<ref>{{cite book |last=Sergent |first=Bernard |title=Genèse de l'Inde |year=1997 |page=113 |language=fr |isbn=978-2-228-89116-5 |publisher=Payot |location=Paris}}</ref>