eg: swimming 10 rounds should be a 30 minute thing, but took more than 2 hours!
eg: played piano only 5 to 10 minutes but the whole session lasted at least 30 min
eg: help wife look for her teaching aids. Took at least an hour.
eg: called grandma for 1.5 hours

brought boy to pingpong;visited library,then blogging;2H: analyzed my insurance needs

boy typing for about 30 min