Legos are fun, but rifling through big, unsorted bags of these plastic bricks to find just the right ones isn't. Third graders at Runnels School in Baton Rouge think they have an answer: a Lego shaker.

Pour in buckets full of Lego pieces and out emerge only the sizes you want. That’s the theory anyways.

Since the beginning of the school year, teacher Candace Ortlieb’s third-grade science classes have been trying to solve this engineering puzzle. While they read up on other Lego sorters, their design is largely a produce of trial and error.

Their first prototype was a three-feet tall, 10-inch diameter stretch of green PVC pipe. It proved too big for a third-grader to shake.

So they cut the pipe into three sections and handles were added. On Wednesday, the kids got to shake it out.

After the first test, with a cache of small Legos at the bottom of the bucket, several students declared victory: “It worked!”

Teacher Candace Ortlieb was more cautious.

“It works, but the smallest size needs to be a little smaller,” she said.

Sorting Legos is a special problem at Runnels. After the 2016 flood, the school received a donation of more than 100 pounds of the pegged bricks. Ortlieb says she uses them for everything.

Her third-graders this year, however, did not relish trying once again to find the right ones. They recalled the difficulty they had as kindergartners making a Lego gingerbread house.

They decided to find a better way. To make that happen, Ortlieb has shepherded them through an eight-step engineering design process.

Step 1 is “Identify the problem." On an index card pinned to the board in Ortlieb’s room is their answer: “Our legos are all mixed up and messy.”

They settled initially on a creating a shaker, or a sieve, with three sections filled smaller rings grouped together. Each ring group allows different sized Legos to pass through. The shape of each ring mirrors that of a toilet paper roll, a glue stick, and a slice of a pool noodle.

For “Design and Construct a Prototype,” the fifth step in the process, the students turned to Brandt Ray.

The father of classmate Paislee, 8, Ray is a manager at Ferguson Enterprises. It's a company that manufactures residential and commercial plumbing supplies. And perhaps more importantly for the students, Ray is a former starting pitcher for the ULL “Ragin’ Cajuns” baseball team.

“I thought it was good that the students got to make a prototype of something, troubleshoot about how to put it together and then actually come up with the end product,” Ray said.

In return for his help, the students presented him a special Lego gift they made: A miniature Tiger stadium consisting only of Legos.

The project is now at step eight, "Evaluate and Redesign." The redesign will take a different approach, in which holes are punched into a plastic drum.

“I think that is going to work better,” Ortlieb said.

She said class projects like these teach kids so much.

“It taught them how to slow down, how to take things step by step and to see that they can look back and say, 'Wow, we’ve been on this journey of this Lego shaker and it culminated into something really special,' so that makes them willing to try something big or daunting next time,” she said.

Ortlieb say the students have been thinking about what do with the shaker once they are done. They even hand wrote a business plan. It makes clear they aren't looking for cash, but then again don’t work for free: "We will sort anyone’s legos for them...in exchange for donuts or cookies.”

They'll make an exception for toys. Definitely toys.