This mat was created in order to assist students in understanding the concept of addition with regrouping. Place the mats into sheet protectors and have students use base ten blocks to manipulative objects inside of the squares provided. Students may push their ones together, into the sum box, and determine whether or not the ones need to be "traded" for a ten. Then the students may gather their tens into the appropriate sum box. Students may record their number sentence using dry erase markers and repeat several examples during this activity.