Since WF Work Study generates 19 hours, must we stack additional activities to get to 20 hours?

No. The 19 hours will be reported as 20 hours. You do not have to stack additional activities for the parent to earn the 1 hour. Here is the explanation of a DSHS staffer:

"Our systems will round up any 10th of an hour to the nearest whole hour, and this is acceptable to the feds. As long as the budgeting is being done correctly, and as long as this is only occurring for those in 19 hours of Work Study, then we do not have to stack additional activities as we are reporting out 20 hours."