Question

What is the best approximation of a 15% tip on a $3

Answer 1

i meant 38$ sorry

Answer 2

$5.70

Answer 3

So 100% of $38.00 is $38.00. That means 10% is going to be $3.80 since we just moved the digit over by 1 to go from 100 to 10.

But we want 15% which is 10% + 5% so how do we figure out the other 5%? Well 5 is half of 10 so we just add half of $3.80.

That's how I'd calculate a tip, but usually I give 20% so I'll just double the amount moved over by 1 digit.

Answer 4

You just change 15% to a decimal, so 0.15, then multiply it by 38

Answer 5

thanks you guys

Answer 6

I'm trying to suggest a practical way of doing it in your head as a method of approximating.

Since 38 is almost 40, you can sort of approximate 15% of 40 which is easier to do since it'll just be $4 for 10% of 40 and that must mean $2 is 5% since that's half of 10% so you could say that $6 is the best approximation of 15% of $38 depending on what you consider "best" approximation to be.

Answer 7

I'm pretty sure this is the method you are looking for that I have just described in the last.

Round to the nearest 10.