Visiting cultural attractions and museums in Massachusetts can be a pricey outing for a family and, with that in mind, many of the state’s largest nonprofit institutions have launched programs that allow attendees to show their electronic benefit transfer cards – known as EBT payment cards – to gain free or deeply discounted admission. The Boston Children’s Museum started the trend with an EBT card discount program it launched in August 2012 and, since then, many major cultural institutions…