MINERAL WELLS, Texas — Desperate to fill open positions amid a statewide teacher shortage, school officials in this rural North Texas city of about 15,000 chose to follow the lead of neighboring districts by converting to a four-day school week at the start of the current student year. “We decided if we can’t beat them, join them,” Superintendent John Kuhn said. As the school year nears a close next month, Kuhn proclaimed the four-day week “a really good success,” which, among other positives, produced a surge of qualified teacher applicants that helped the district fill its vacancies. The seven-member school...