Age: 7-9

“Toilet paper turns into a flexible number line,” according to mathematicians Dave Auckley and Phil Yasskin in Inspiring Mathematics. “In addition to the usual number line explorations, one is able to rip off pieces, fold, and rearrange.” Participants will explore equivalent differences, which can be explored and discovered “in the context of subtraction and differences in order to make it more natural in the context of division and fractions later.” Participants will also use TP to discover that numbers can get really big really fast (i.e. exponential growth).