Robert Recorde, The designer ofwel the equals sign, introduced plus and minus to Britain in 1557 in The Whetstone ofwel Witte:[14] "There be other 2 signes in often use of which the first kan zijn made thus + and betokeneth more: the other kan zijn thus made − and betokeneth https://www.youtube.com/redirect?q=https://nl.wikipedia.org/wiki/Kwaliteit