First number is the number of HE (high explosive) rounds you have. The second is the number of AP (armor piercing) rounds you have. You use one every time you take a shot. The program selects which type of round is appropriate for the target. (you can't choose)
For infantry squads, each man has whatever weapon is in slot 1 (rifle). The squad also carries one of each of the weapons carried in slots 2, 3 and 4. So, in your example, if you had a 10 man squad one guy would have a SMG, another guy would have a bazooka and a third would have the flamer. The remaining 7 men in the squad would each have a rifle.
Its what you do
and not what you say
If you're not part of the future
then get out of the way
That is ammunition - the number of times the unit can fire before having expended all the ammo it is carrying. HE is used against soft targets such as infantry. AP is used against hard targets like tanks. You'll see that some weapons have 'HEAT' and 'SABOT' ammo as well. These are also used against hard targets.
Regards,
Lars
"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin