A mathematical historian at Trinity Wester University in Canada, has found use of a decimal point by a Venetian merchant 150 years before its first known use by German mathematician Christopher Clavius. In his paper published in the journal Historia Mathematica, Glen Van Brummelen describes how he found the evidence of decimal use in a volume called "Tabulae," and its significance to the history of mathematics.

Prior to this new discovery, the earliest known use of the decimal point was by German mathematician Christopher Clavius as he was creating astronomical tables—the resulting work was published in 1593.

Glen Van Brummelen, a mathematical historian at Trinity Wester University in Canada, has now found use of a decimal point by a Venetian merchant 150 years before in a manuscript written by Giovanni Bianchini in the 1440s.

Giovanni Bianchini worked as a merchant in Venice for many years before being appointed to an administrative role with a major estate owned by the powerful d’Este family. In this role, he also managed assets and investments, giving him a strong background in mathematics. He also published astronomy texts, demonstrating his ability to plot planetary motion and to predict when an eclipse would occur.