Roy uses 1/4 cup of butter for each muffin make a list to show the amount of batter he will use depending on the number of muffins he makes

2 muffins: 1/2 cup of butter.

3 muffins: 3/4 cup of butter.

4 muffins: 1 cup of butter.

5 muffins: 1 & 1/4 cups of butter.

6 muffins: 1 & 1/2 cups of butter.

7 muffins: 1 & 3/4 cups of butter.

8 muffins: 2 cups of butter.