On a recent Thursday, math teacher Beth Wendell is teaching her 3rd graders at Mastery-Clymer Elementary School in North Philadelphia how to add two-digit numbers.
She’s written a problem on an easel wedged into the corner of the room:
You know how to solve this problem right? Add the right column of numbers. Carry the one. Add the second column of numbers. Voila.
But Wendell doesn’t go that route — at least not at first. Instead, she directs her students to reach into large plastic bags filled with little counting Lego-style items called base-ten blocks. Their purpose is to teach students the basic concept behind addition so they can feel and see what these numbers mean. The number 11 is represented, for instance, by one little block and one larger block made of 10 little blocks glued together.
When students collect 10 of the little blocks, they can exchange them from one of the larger blocks. After some coaching and counting, the students stumble toward the right answer.
Then Wendell swings over to the easel and does the same problem using the familiar “paper and pencil” method. Finally, she offers her students a choice.
“When we do our next two together, we’re going to use base-ten blocks and paper-pencil to see which one you like better,” Wendell says. “You will get to choose.”