People

How many is a million? Betty Hester knew she could teach the concept, but she wanted her students to grasp the idea by actually seeing what a million of something looks like.

"It's hard to get students to visualize a big number like one million," said Ms. Hester, a 7th and 8th grade math teacher at John Adair Middle School in Columbia, Ky. So to help her students along, she decided to have them start a collection. They chose soda-can pull tops.

"We got started on the project two months ago, but we are already a third of the way there," Ms....