00:00 Count only open tasks
00:24 Keep the data model simple
00:51 Name the decision
01:18 Static methods use double colon
01:46 Set up an accumulator
02:14 Visit one element at a time
02:37 Let a condition control the update
03:02 Trace the values by hand
03:28 Run the working example
03:54 Check the boundary cases
04:23 Separate responsibilities
04:51 Exercise: choose another state
