Thousands of Utah youngsters said goodbye to summer and hello to school Monday, trooping back to classes in all but a handful of the state's districts.

More than 420,000 students have begun the 1988-89 school year. An official count won't be taken until mid-September, state school officials said, but the number is expected to increase by several thousand over last year's count of nearly 423,400.Nevertheless, Monday marked the end of vacation for the great majority, and neighborhoods were emptying early in the morning, spilling their children into schools for the beginning of another nine-month stint.