Robert Recorde, The designer ofwel the equals sign, introduced plus and minus to Britain in 1557 in The Whetstone of Witte:[14] "There be other 2 signes in often use ofwel which the first is made thus + and betokeneth more: the other is thus made − and betokeneth lesse." Lamentablemente, https://www.metooo.co.uk/u/6838c7ba9c4139531f4fdfb8