Round up scores
Canvas has grading schemes which will help you round up or change the decimal points to whole numbers for grade totals. You can do this by enabling the grading scheme within course settings. However, if you have a quiz that has point values that would incur decimals or half points, no there isn't a feature to round up new quiz grades - it would unfortunately need to be changed manually in the gradebook or you can continue doing it the way you have. it isn't ideal but you'd need whole point answers and questions within your quiz to overcome decimals within their grades.