Do 2 Samuel 10:18 and 1 Chronicles 19:18 contradict?

2 Samuel 10:18 says:

"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."

1 Chronicles 19:18 says:

"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."

The two verses do not contradict.  2 Samuel 10:18 describes the deaths of an unspecified number of men who rode in "seven hundred chariots".  1 Chronicles 19:18 describes the deaths of "seven thousand men" who rode in an unspecified number of chariots.  In other words, 2 Samuel 10:18 gives the number of chariots and 1 Chronicles 19:18 gives the number of men.  Therefore, putting the two verses together we know that there was an average of 10 men to each chariot.