By adding a rubric to an assignment/quiz/graded discussion, you do not even need to type the grades. Simply clicking on the rubric in SpeedGrader, the rubric points will be automatically populated in the grade field. For details, check out this tutorial.
Want to get your grading done wherever you happen to be? The Canvas Teacher app lets you easily flip through and grade assignments with your tablet or smartphone. Download it now from iTunes or Google Play.