Answer: If I am correct you should end up spending $74.06
Explanation: To find out how much a 15% tip will be you have to multiply $64.40 by 0.15 by doing this you should get $9.66 this is how much a 15% tip is with the amount of money spent. Then add $9.66 to $64.40 then you should get $74.06
Ok, make sure you put the powers correctly. I know what you mean but someone else may not. So it's step 2. This is because the 4 doesn't mean add a digit.
