"Traction"

JJ told me tonight as he was getting ready for bed that he knows how to do "traction." I asked him what traction was and he said, "you know like adding numbers together."  Oh! Addition!  He then gave me an example, "mom, I know what 80 plus 40 is."  He thought a little bit and said, "120."  He then told me how 40 plus 40 is 80. I cannot even tell you how impressed I was that my 6 year old can add that well.