No one has to tell Cheryl Hennessey that Utah has the largest classes in the nation. When school opened last fall, 38 pupils were squeezed into her first-grade class at Salt Lake's Washington Elementary School.

"With 38 in a class, it's very hard to start their education," Hennessey said.Washington's other first-grade teacher also had a classroom crammed with 38 pupils. Washington's first-graders were eventually divided into three classes, with Hennessey's class dropping to a more manageable 22.

It was Hennessey's room of 6- and 7-year-olds who shyly flanked Gov. Norm Bangerter Tuesday as he signed into law the class-size reduction bill, sponsored by Sen. Dix H. McMullin, R-South Jordan. The new law will pump $4.8 million into Utah's first grades in the next school year."It's nearly $5 million in the first grade so your classes will be a little smaller," the governor told his pint-sized observers.

Smaller classes mean "your teachers can have more time to spend with you," he explained to the children.

Utah Education Association President Lily Eskelsen clapped when Bangerter asked how she felt about the new law. "It's one small step for first grade, one giant leap for class size," she said.

The 1991 Legislature, in its final days, appropriated the $4.8 million from the Uniform School Fund to reduce class size in the first grade by three students.

The new average classroom size will vary by district. In Salt Lake School District, where the bill-signing took place, the new infusion of money means that - theoretically at least - the district's average first-grade class size should drop from 25 to 22.

"In some cases, as will be the case in other districts, it will mean more first-grade sections. In other cases, there may not be room, so we'll give other support," Salt Lake Superintendent John W. Bennion said.

A likely form of that other support would be a teacher's aide, he said.

One problem that school districts may encounter in trying to reduce first-grade class sizes is increased competition for a smaller pool of teachers.

Last fall, Salt Lake and other districts "noticed a reduction in candidates for kindergarten (teaching positions)," said Bennion, who is also president of the Utah School Superintendents Association.

About three years ago, the University of Utah dropped its early childhood program, which covered preschool through second grade.

"We are engaging in conversations with the University of Utah to see if we can resurrect the program, at least as an alternative program," Bennion said.

Brigham Young University still has an early childhood education program and graduates the majority of the state's new teachers annually. But, Bennion pointed out, many of those new teachers are out-of-state residents who return home after completing their college education.

Legislators indicated that next year they will try to allocate money to reduce class size in the second grade.

"My belief," Bennion said, "is that before going up the scale, they ought to come back to kindergarten and do it. After second grade, they should reduce class size in kindergarten."

Kindergarten no longer consists of play time and crackers and milk. Kindergarteners learn skills vital to their success throughout school, the superintendent said.

"There is a lot of prereading and premath activity. The kids are so dependent on the teacher, and they need as much teacher time as possible," Bennion said.