Hold on to your graphing calculators: The passionate, contentious debate over how California students should learn math is ready to erupt again.

While math formulas and properties may be delightfully precise, how best to teach them to children is not. As the United States prepares for the first time to adopt nationwide K-12 "common core" standards, mathematicians and educators are split.

Some hail the proposals as a groundbreaking advancement because students will develop a more solid footing in math before rushing to the next level; others fear the plan would propel California backward. Each side warns that America's future as a global science and technology powerhouse is at stake.

Fast-tracked by the Obama administration, standards for what students should learn in English and math have been drafted by a national committee representing 48 states and the District of Columbia. The public has until Friday to submit comments. California can choose not to adopt the federal standards but would miss out on competing for hundreds of millions in federal stimulus dollars.

While the proposed English curriculum hasn't provoked an outcry, the math debate echoes California's "math wars" that raged in the 1990s and led to repeals of reforms that favored problem-solving, applications and group work over traditional teaching.

Under the new proposed standards, primary students would spend more time going in depth on ntil