The students at the Varnum Brook Elementary School in Pepperell groaned in unison when teacher Karin Pillion announced they would do the next set of problems out loud — without pencil, paper, or calculators.

“What is 6 times .04?” Pillion began.

Multiplying decimal points in their heads is not something fourth-graders in the North Middlesex Regional School District were doing a decade ago. But despite the groans, the class on Monday morning moved confidently through a dozen problems, using a method known as Singapore Math.

“I have seen kids go a long way with Singapore,” said Pillion. “Even those that came to class at the beginning of the year with math phobias are up to speed.”