[HOTTIEBOY]

IMO, if you can't calculate 15 % in your head, you should be eating at home.

Well you just wiped out 80% of the resturant business.
Whats 15% of $36.24? quickly quickly quickly now add it to get the total, quickly quickly.

New Communist Reform Law: Those who are not Fields Medalists are not allowed in resturants.

What scares me is how boring a resturant would be if only people that could calculate 15% were there.

[Tenniel2]

Easy:

10% of $36.24 is $3.60 (ignore the pennies)
Half of $3.60 is $1.80 (you can divide by 2, can't you?)
$3.60 + $1.80 = $5.40
$36.24 + $5.40 = $41.64, which is pretty darn close to the calculator-derived total of $41.68.

And no, I've never been accused of being a boring dinner companion.
What scares me is a restaurant full of the sort of people who worry about calculating tips to the third decimal...

[Nonstatist]

Starting with $36.24..Calculate 10 % real quickly, can you do that? Thats about $3.60, just move the decimal over one.. not hard, is it? Now half that is $1.80. Still easy, right? Now add them.. $ 5.40 Easy, wasn’t it? Not exactly rocket science, is it?