ROCHESTER, N.Y. — Jennifer Craig stared at her daughter’s fifth-grade math homework. It was a three-digit multiplication problem, and it seemed simple enough. But her 10-year-old was supposed to solve it by drawing a chart, breaking apart numbers, multiplying, adding and maybe more.

“I’m lost,” said Craig, a 31-year-old stay at home mother of three.

And that’s how she found herself in her daughter’s classroom Monday night, sitting alongside other parents in child-size chairs and listening as teacher Alyshia Thomas explained new math strategies.

Most U.S. public school students are learning math very differently than their parents did, due to Common Core State Standards, national K-12 math and reading benchmarks that have been adopted by 43 states and the District of Columbia.

The changes have confused many parents — particularly at the elementary level — leaving them flustered by a basic parental duty: Helping with homework.

“Almost every parent comes in and says, ‘This is not how I learned math,’ ” said Melissa Palermo, an energetic fourth-grade teacher who coaches other teachers in math at the Nathaniel Hawthorne school here.

Palermo is a believer in the Common Core, a wholesale and controversial change in American public education, because she says her students are reaping the benefits of the new standards. They are showing a more sophisticated understanding of math and are able to perform operations they otherwise wouldn’t have learned until they were older, she said.

But parents are another matter.

“The toughest part is the homework part because parents, it’s so hard for them,” Palermo said. “A lot of parents, they doubt themselves because there are all these models and things they’ve never seen before.”

Rochester is one of many school districts across the country teaching parents the new Common Core math in addition to their children. From New York to California, school districts are holding special math sessions for parents and caregivers, sending home “cheat sheets” and offering homework hotlines answered by math teachers, all in an effort to explain and demystify the new approach.

“The kids who come to us are a clean slate,” said Jennifer Patanella, an instructional coach with the Rochester public schools. “It’s the adults who have to be retrained.”

In Las Vegas, Bill Hanlon is teaching a five-month course in new math strategies to a group of approximately 50 parents.

“They’re a little frustrated because they can’t help their kids,” said Hanlon, who directs professional development for math teachers in five Nevada school districts. “One of the messages I give to teachers is that if you’re going to send home stuff that parents have not seen before, send a note explaining, this is what we’re doing and why and a couple of examples. Otherwise, you’re going to get a lot of complaining.”

Diane Dunaskiss, principal of the Pine Tree Elementary School in Lake Orion, Mich., about 40 miles from Detroit, has been looking for ways to make Common Core math relevant to her students and their parents.

Two weeks ago, her school hosted a Common Core math night for families the local Kroger’s supermarket. Children and adults were given everyday challenges requiring math operations, such as figuring out how many boxes of pasta to buy for a dinner for six if each box contains four servings.

“The new math standards are encouraging students to think deeper,” Dunaskiss said. “Part of that deeper understanding is to take what you’ve learned and apply it to what you’re doing in real life.”

A bipartisan group of governors and state education chiefs created the Common Core State Standards in math and reading in 2010 as a way to inject consistency into K-12 academic standards, which have varied wildly from state to state. The standards spell out the skills and knowledge students should possess by the end of each grade. They are not curriculum — states and school districts decide how to teach to the standards and what materials to use.

In the past, math was learned as a series of memorized facts, formulas and shortcuts or tricks. The result, experts say, is that U.S. students struggle with math. Nearly two out of every three U.S. fourth-graders and eighth-graders were not proficient on recent national math tests. The Common Core standards differ from that previous approach in that they emphasize the concepts behind mathematical operations and stress that there are multiple ways to arrive at the same answer.

In primary grades, math instruction begins with “manipulatives,” such as blocks or beads, and progresses to drawings, number lines or graphical groupings. The idea is to teach children to think about a number as more than just a symbol. The Common Core standards expect students to not just calculate the answer but to explain how they arrived at the solution. Word problems are heavily used, and that has raised concerns by some that Common Core math is particularly hard for English language learners and students with learning disabilities.

Despite the fast and widespread adoption of the Common Core standards, opposition has been growing from critics across the political spectrum. Some of that outcry has been fueled by classroom materials that are poorly designed and confusing.

In St. Tammany Parish, La., the school board voted on Oct. 9 to ditch Eureka Math by next school year after parents complained that it is overly complex. Board members, many of whom generally oppose the Common Core standards, made the move over the objections of some teachers who argued that the curriculum was worth keeping. U.S. Sen. David Vitter (R-La.), also voiced concern, asking the state education department to stop recommending that districts use Eureka Math.

Lynne Munson, executive director of Common Core Inc., the nonprofit organization that created Eureka Math, said there have been “extraordinary stories of success” in Louisiana and elsewhere.

It would be a “terrible disservice” if school districts stopped using Eureka Math, Munson said. About 15,000 people have downloaded a free version of Eureka Math from Common Core Inc.’s Web site, and the organization has trained about 7,000 teachers to teach the curriculum, she said.

Because the rollout of the Common Core has been fast — the standards were written just four years ago and publishers have been rushing to develop classroom materials — many say the quality teaching materials, worksheets and homework is uneven.

In April, comedian Stephen Colbert ripped into an example of a math problem that had lit up the Web after it was posted on Facebook by a frustrated North Carolina father. The homework problem showed a horizontal number line with a series of half domes scribbled on top and said “Jack used a number line below to solve 427-316. Find his error. Then write a letter to Jack explaining what he did right and what he should do to fix his mistake.”

“That’s a great question. It teaches two important workplace skills: math and passive- aggressive note-writing,” Colbert quipped. “That word problem couldn’t be easier to solve. All you have to do is check the semi-circles on the two-sided arrow, put the numbers up in it and bing, bang, math. It’s the same thing I do when I get a check in a restaurant. Draw a bunch of shapes and tell the waitress to find my error.”

The parent who posted the math problem, Jeff Severt, wrote the note required by the problem: “Dear Jack, Don’t feel bad. I have a bachelor of science degree in engineering which included extensive study in differential equations and other higher math applications. Even I cannot explain the Common Core mathematics approach, nor get the correct answer. In the real world, simplification is favored over complication.”

Then, he solved the problem using simple subtraction, which he said took less than five seconds, to come up with the answer: 111.

In Rochester, more than 200 parents, guardians and students showed up for the recent “Family Do the Math Night,” one of seven the district is holding this school year. The school district, where 84 percent of the 30,000 students are eligible for free or reduced-price lunch, offered free dinner and door prizes as an incentive.

“I’m not prepared for this. I’ve been out of school since ’77,” said Vivian Gambill, the mother of an eighth-grader. She said the event was helpful, but she remained baffled by some of the material. “I’m still having some struggling moments. But now I have some Web sites I can go to.”

Willie Howard, 65, sat in the cafeteria with his two granddaughters and followed the teacher’s directions to subtract 23 from 46 by drawing a series of circles. He understood the method but wasn’t entirely sold.

“I don’t know about this,” he said, considering all the circles he’d drawn. “There’s a whole lot more process to this. And kids, they get distracted easy. They say it’s better. But I don’t know.”