That would be 9/12 left over. Actual Math: Change 1/6 to 2/12. Why you may ask? Well, they are both equivalent. Then, add 1/12 + 2/12 which equals 3/12. After that,subtract 12/12 (total) - 3/12. You should get 9/12, your answer to the problem. So, Jonathan has 9/12 of his favorite pasta left over.