If you don't know math, then yes. Most people don't know or care that "adding 5% tax" is equivalent to multiplying by 1.05. They just know that you have to add 5% for tax. So 72 + 5% makes perfect sense; 72 * 1.05 is terribly confusing.
But that's why most people get stuck with percentages, even if you give them a calculator.
They can work out what 8% of 347 is. But ask them what 43 is as a percentage of 172 and they can't do it. Or if a widget costs £250 after a 20% discount, how much did it cost before -- they can't do it.
This actually puts these people at a disadvantage in real life. Just look at the arbitrary packaging sizes and how effective they are at fooling people into thinking they're cheaper or equally expensive just because they're unable to figure out that the "new packaging with 25% extra for free" is actually more expensive than the old packaging that contained a little bit less.
