@ekename,
No! Ekename. You can not say "call and raise 3".
What you are suggesting is a string bet. It is against the rules. In any real poker room or casino, if you did that your raise would be nuliffied (turned into a call) and you would be warned. If you did it reapeatedly you would be penalized.
The rule is that you need to make a bet in a single action.
If someone says "raise 8" it will be interpreted as "raise to $8". I play tournaments one or two times a month in a poker room, or Foxwoods (and occasionally other casinos). It has always been that way.