How do you calculate extra credit assignments? Note I said multiple assignments. We created an extra credit category and then put in an insignificant number for the point value for one column. We found that 0.001 would be do the trick since Blackboard's categories must have some value greater than 0 and that number had a very small impact on the total possible points total for the overall percentage grade. After we migrated to Q2 2016 CU7 our hack stopped working. We now have to make sure the category has a possible value of 1 which has more impact when calculating percentages for grades than our terribly insignificant number. Of course, being to have no value would be best in terms of extra credit.