Question

Laura is baking a cake. The recipe says that she has to mix 64 grams of chocolate powder to the flour. Laura knows that 1 cup of that particular chocolate powder has a mass of 128 grams. She added two over three of a cup of chocolate powder to the flour. Should Laura add more chocolate powder to make the exact recipe or did she go over and by what amount?
She went over by one over three of a cup

She needs to add one over three of a cup

She needs to add one over six of a cup

She went over by one over six of a cup

Answer 1

The answer is She went over by one over six of a cup

1 cup of that particular chocolate powder has a mass of 128 grams: 1c = 128g

64 grams of chocolate powder is x cups.
1c = 128g
x = 64g

1c : 128 g = x : 64g
x = 1c : 128 g * 64 g
x = 0.5 c
64 grams of chocolate powder is 0.5 cups = 1/2 cups

She added two over three of a cup of chocolate powder: 2/3 cups

She need to add 1/2 cups: 1/2 = 3/6 cups
She added 2/3 cups: 2/3 = 4/6 cups

So she added 4/6 - 3/6 = 1/6 cups more.