The state's top school official wants Arizona businesses to let staffers take time off to teach.

Superintendent of Public Instruction Tom Horne says Arizona needs 70 new math teachers a year, just to keep up with those who are retiring or leaving the field.

But that, he said, is just the beginning. In his annual State of Education address set for delivery today, Horne says the state must have 400 new teachers to implement new requirements for the class of 2013 to have twice as much math as the two years now required to earn a diploma.

Horne said the education programs at state universities are working to turn out more graduates. And he said the state also is funding efforts to convince teachers in places such as South Dakota that they might want to relocate to a warmer climate.

But Horne said some of the gap is going to have to be made up by professionals who are experts in their own fields.

"We're asking businesses to make available highly knowledgeable employees to teach one course a year," Horne said in explaining his plan Monday. He said the emphasis will be not only in math but also in science, where the graduation requirement for the class of 2013 is increasing from two credits to three.

Would-be teachers would have to complete a summer course offered by one of Arizona's state universities on everything from teaching techniques to how to control a classroom. Then, while they were teaching, they'd have to become certified.