Yeap Ban Har broke a simple magnetic rectangle into smaller parts on Wednesday at Lanier Charter Career Academy, as a group of more than 50 local teachers watched.
He was demonstrating the concept behind Singapore math — understanding over memorization. The rectangle represented the whole, and its parts fractions.
"I just learned why you cross multiply," said Beverly Moody, math teacher on special assignment, laughing.
Hall County teachers have been using the Singapore method for the past five years. But on Tuesday and Wednesday, teachers had the rare opportunity to work with Ban Har, a pioneer of Singapore math and principal of Marshall Cavendish Education, a K-12 educational publisher in Singapore.
Ban Har said many teachers show their students how to do something a calculator can do.
"We are not teaching computation here," Ban Har said. "We cannot. It's a big disservice to everyone and the economy if we are teaching for computation. We are teaching them what a cheap brainless thing can do. It's a big disaster.
"We are using (Singapore math) to do many things, including seeing things from a different perspective."
Superintendent Will Schofield said mathematics education in this country has historically been about memorization and algorithms.
"With what we're seeing in industrialized nations that are leading the world, we're seeing that math is a mental exercise and it's taught as a mental exercise," Schofield said.
Kristin Finley, instructional coach and eighth-grade math teacher at North Hall Middle School, said that she has noticed a difference in both her classroom and her home since the county started implementing the principles of Singapore math.
"My daughter has Singapore math and my son did not. The way she thinks is completely different," Finley said. " I ask her to tell me how she came up with a solution and I go ‘What?' It's amazing what she can tell you about her thought process."
Moody said two days of training under Ban Har have given teachers a lot of "aha moments" and challenged them to examine the way they teach.
Finley said as a strategy for problem-solving she sometimes asks her students to draw a picture.
"They don't know what that means. This gives them a concrete example. They start drawing a rectangle and they go ‘OK. I know this represents a whole,'" Finley said.
Moody said having the elementary and middle school teachers together at the training session is going to help pull the lessons together across grade levels.
"These concepts need to be K-12. It's not just the actual teaching of the math, it's the whole concept of the teaching," said Melissa Stewart, math teacher on special assignment.