Does anyone know why this happens???
So I got a $20 gift card and I'm trying to spend exactly $20. I was trying to make my order exactly $20 including the authorization, and for my items, with a 9% tip of $2.29, my total was $19.10 and I'd be charged $19.67. But since im trying to make it exactly $20, I tried increasing the tip little by little until I got my amount. However, when increased it by just 1 cent, my total shot up to $19.82 and would be charged $20.41. Why is my total shooting up 72 cents just because I increased the tip my a penny????