Chinese Abacus. The abacus is first known in China from the Northern Song dynasty through the work of Shao Yong (1011-1077). Like many early inventions it is not clear precisely where it originally came from. Some say Central Asia; some Asia Minor and others China.
Snag(noun) a stump or base of a branch that has been lopped off; a short branch, or a sharp or rough branch; a knot; a protuberance. Snag(noun) a tooth projecting beyond the rest; contemptuously, a broken or decayed tooth.
frag. n. A fragmentation grenade. tr.v. fragged, fragÂ·ging, frags. To wound or kill (a fellow soldier) by throwing a grenade or similar explosive at the victim: He got fragged.