Robert Recorde, The designer of 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 of which the first is made thus + and betokeneth more: the other kan zijn thus made − and betokeneth lesse." https://wastesunday1.werite.net/bekijk-dit-rapport-over-wrapfolie-avery