There's something about the whiteboard, new dry erase markers, and a challenge that makes students excited about math. Does having the space of a whole white board make them feel like a teacher? Is it something tactile about the smooth sensation one gets while using the marker? Or is it visually appealing to do math in pink or purple with big numbers? Either way, the students at HRC love to be given math problems that they can solve on the whiteboard.
A few days ago, one of the students asked about a type of multiplication that we learned a while back called lattice multiplication. He wanted to remember how to do it, so I had the students in this group see if they could recall the method while working in teams. Lattice multiplication was a part of a series of "cultural multiplication" we studied, and has roots in Arab, Chinese, and Indian schools, dating as far back as the late 13th century.
All of the students eventually were able to figure out lattice multiplication-- some even challenged themselves to solve a 10-digit multiplication problem!
Below is a video by Khan Academy that explains the process:
Lattice Multiplication: Introduction to lattice multiplication