Emily's bill for dinner at a restaurant was $61. She left an 18% tip. What was the amount of the tip?

You cross multiply. So 61 over 18 = x over 100. You multiply 61 and get the answer of 1600. Now with what you have left, you divide that with 18 and you should get your answer of 338.888889. Make sure to round it to whatever it tells you to round to!