Mary is baking a cake. The recipe calls for 11 cups of sugar and 9 cups of flour. She already put in 12 cups of flour and 10 cups of sugar. How many more cups of sugar does she need to add?
First, we need to find how many cups of sugar the recipe calls for. 11 cups of sugar is the same as 11/1 cups of sugar, so we can say that the recipe calls for 11/1 cups of sugar. 

Next, we need to find how many cups of flour the recipe calls for. 9 cups of flour is the same as 9/1 cups of flour, so we can say that the recipe calls for 9/1 cups of flour. 

Now, we need to find how many cups of sugar Mary has already put in. 12 cups of flour is the same as 12/1 cups of flour, so we can say that Mary has already put in 12/1 cups of flour. 

We also need to find how many cups of flour Mary has already put in. 10 cups of sugar is the same as 10/1 cups of sugar, so we can say that Mary has already put in 10/1 cups of sugar. 

Now, we need to find how many more cups of sugar Mary needs to add. The recipe calls for 11/1 cups of sugar and Mary has already put in 10/1 cups of sugar, so she needs to add 1/1 cups of sugar