[Lonesome in Massachussets]

A company of infantry (= a battery of artillery or a troop of cavalry) is about 120-200, four platoon plus headquarters. A battalion is generally about four companies, plus headquarters and support troops, about 800 men. Generally the ratio of killed to seriously wounded is about 1:4, so killing 100 would generally result in about another 400 seriously wounded. If you inflict north of 25% casualties, killed and wounded, on a unit it may lose cohesion and the ability to function. Some U.S. units during the Battle of the Bulge suffered 80% casualties, but the survivors continued to fight as a unit. A lot depends on the level of training and morale.

[sinanju]

Something tells me Hamas has some mighty generous numerical standards as to unit numbers.