Who said high school math wouldn’t come in handy?
In Germany, the price you see listed includes the 19% tax. There are times when we don’t have to pay the tax and so, for big ticket items, we try to figure what the price would be without sales tax.
Jon’s method was to multiply the total price (T) by.19 and then subtract it to get the pre-taxed price (x).
T -.19T=x or simplified, .81T=x
This is NOT the way to do it.
Why? Because the 19% tax is figured from the pre-taxed/original price (x). So, the right way to do it is…
x+.19x=T or simplified, x=T/1.19
Confused? Let’s look at an example. Let’s say we want to buy a sofa. The price tag says 430 euro. So, T=430. We don’t have to pay tax and want to know how much the pre-taxed pirce (x) is.
Jon’s way: My way:
.81T=x x=T/1.19
.81(430)=x x=(430)/1.19
348.30=x x=361.34
As you can see, Jon’s way will give you a nasty surprise at the checkout. You’ll end up paying more than you were counting on.
Finally, my five years of calculus and year-and-a-half tutoring high school algebra can be put to good, practical use.












