HOW MANY DID DAVID'S ARMY KILL WHEN BATTLING SHOBACH?

II Samuel 10:18 And the Syrians fled before Israel; and David slew the men of seven hundred chariots of the Syrians, and forty thousand horsemen, and smote Shobach the captain of their host, who died there. (KJV) I Chronicles 19:18 But the Syrians fled before Israel; and David slew of the Syrians seven thousand men which fought in chariots, and forty thousand footmen, and killed Shophach the captain of the host. (KJV)

Like with the previous question, it would be easy to confuse 700 and 7000 when transcribing, so this was almost certainly a transcribing error and not an error in the original texts.  As for horsemen vs. footmen, many soldiers are able to fight on both horse or foot, so the 40,000 here could easily be described as both 'horsemen' and 'footmen'.  Not a contradiction.