Quick: What's 9 x 17? David Holliday can do it in his head, not just because he's a math teacher but because he breaks it down as 9 times 10 and 9 times 7 before adding the two.

It's called number sense; breaking numbers apart and putting them back together in different ways. Maybe it's not how you were taught multiplication but it's one way kids learn.

"I call it Lego math sometimes," the Tri-Valley Middle School math teacher said. "You take it apart and put it back together. There's more than one right way to do things. The answer's not the focus any more. It's the process."

And the process is changing, with an emphasis on problem-solving rather than rows and rows of practice problems in inch-thick books. Remember the word problem about the train leaving the station? It's still there, but students also are asked to calculate target heart rates, fat grams and how many CDs they can buy with $39.

Cindy Langrall opened a math lesson with a triangular figure and an exercise that asked students to stretch the figure with rubber bands, changing the dimensions.

"They will sort of bump into the mathematics," said Langrall, a math professor at Illinois State University. "It's in there. It's very engaging and a higher level math than what you'd see in traditional textbooks. We're expecting a deeper level of understanding. Before, we did a lot of things superficially."

So superficially that she despised math in elementary school and cheated off a boy in sixth grade.

"I cried learning math tables," she said. "I hated it."

Problem solving has become the new vehicle for learning math, Langrall said. And there's more than one way to arrive at the same answer.

"Long division is long division, but when we were in school, there was only one way to do it. Now there is more than one."

Although today's math books may baffle parents, it's not "new math," the term coined in the '60s for the dramatic change in the way math was taught in an attempt to make Americans more competitive with Soviets in the space race. New math died in the '70s when abstract concepts like set theory and number bases other than 10 lost students and teachers.

The pendulum swung back hard, with a shift to the basics, memorization, skill and drill. But that didn't boost test scores either. Students usually hit the wall in one of two areas, Langrall said, algebra or geometry.

"A lot of times the level of instruction was too far removed from their level of understanding. You can't memorize all the things you need to understand."

And then came the '80s, with the technology explosion. Who needed to know how to figure percentages when there were powerful calculators and number-crunching computers?

"The truth is, technology has changed what's important to know," Langrall said. "But with calculators, it's critical students have a strong number sense. We can't have them pushing in numbers blindly and not knowing if the answer's right."

On a classroom board, Holliday's students figured the percentage of cell phone minutes used, graphing the results in a circle. Math is getting tougher to sell, he said.

"By eighth grade, they know the technology is out there. They see mom and grandma using calculators and they're using powerful computers themselves."

Megan Marquis of Normal keeps a calculator in her backpack, but in fifth grade, she was struggling with fractions. Her mother tried but couldn't help much.

"I went so far as to call the teacher because I thought the system was faulty," Jeanne Marquis said. "Looking back, I think they skipped a few of the basics. They were teaching all these advanced manipulations of fractions without making sure she understood the fundamentals."

She bought a couple of workbooks and tutored her daughter, who's now in advanced math.

Parents can help by asking questions about the assignment, reviewing examples and supporting, but not doing, the work. And remember, their division may be different from yours.

"You can't judge their method," Holliday said. "You have to let them do it their way. The developmental process with math goes from the abstract to the concrete and they're all in a different place."

To hurry homework along, parents may suggest shortcuts the kids aren't ready for.

"They might have to go the long way sometimes. Once they learn that the long way works, they become more curious - 'is there an easier way to do this?'"

As for whether the latest approach to math is working, Langrall said it's too soon to tell. Standardized tests tend to measure computation skills rather than a broader understanding of math.

Tammy Valentine of Bloomington didn't want her two daughters' math skills to slide over the summer. She rewarded her two girls for working lessons three times a week. Sarah, a fifth grader, thinks she'll probably use math in her career, whatever that might be.

"I hope to be a designer," she said. "But I think it'd be really cool to be a policeman or maybe somebody who discovers things, like an inventor. No, probably a lawyer."

And how would a lawyer use math? She came up with a word problem.

"I suppose if there's a person who committed a crime somewhere and I'm a defense attorney and the person said they were somewhere at a certain time, you could use math to tell how far away they were."

Homework help

Whether you loved it or hated it, here are some ways you can help your child with math homework:

• Ask questions. Find out what they did in class that day. Ask to see an example. Ask: What words or directions don't you understand? Where do you think you should begin? Where can we find help in your book or notes?

• Avoid showing them how you would do it. There are several ways to get the same answer and your way may only confuse them. Ask what formula the teacher used.

• If they're stuck, have them estimate the answer. If they do that, they'll know if what they come up with is close to correct. Another way to approach it is to solve an easier problem first, such as replacing decimals and fractions with whole numbers.

• Give them enough time. Sometimes parents rush kids through homework because they're in a time crunch and are trying to hurry the process along.

• It's not your homework. If you do the work, you're teaching the wrong lessons: that it's OK to give up and look to others to solve your problems rather than being resourceful or persistent. Correcting all their mistakes isn't the right approach either. Homework is feedback. It tells the teacher what the student knows and doesn't know.

• Maybe you were a wiz at math. Or maybe not, but telling them how easy it was for you or that you were never good at math doesn't help. If you're stumped by a lesson, let them see you struggle through it too. Stay positive. Negative attitudes are contagious.

• Find help. Math teachers often have Web sites and offer to meet with students before and after school. Maybe your child could call another student for help or the school may have a homework hotline.

• Take a break. If the child is getting frustrated, suggest a short break.

• Make math fun. Log onto math Web sites for skill-building games. Board games, card games and puzzles also develop math skills.

Math Web sites

Some textbooks have a corresponding Web site. Math teachers also build their own sites with homework assignments, sample problems and skill-building games. Here are some math sites Tri-Valley Middle School teacher David Holliday recommends for homework help, practice, tutoring and games on everything from simple addition to calculus:

• www.aplusmath.com

• www.math.com

• www.mathgoodies.com

• mathwords.com

• mathworld.com (more advanced)