Working your abs by lifting weights? It seems ineffective since everybody wants to do hundreds of ab crunches.
You do not have to do all all of those crunches to build six pack abs.
It is not very effective and they strain your back and neck.
To burn the belly fat that is covering your abdominals you should not just focus on ab exercises.
Lifting weights is very effective for burning belly fat faster and building muscle.
But this does not mean you should be doing isolation movements like bicep curls.
Why limit yourself? Instead do compound exercises like squats, deadlifts, lunges, chest presses, shoulder presses, rows, and chin ups.
All these are powerful fat burners especially for belly fat.
They work more than one muscle and speed up your metabolism for hours.
Then you should be doing some effective ab exercises so that you actually work them.
Although they are not effective for losing belly fat like compound exercises are, they still target your abs.
Ideally each workout should consist of about 4-6 weight lifting exercises and 1 or 2 ab exercises.
Some of the most effective ab exercises include hanging knee raises, crunches on an exercise ball, and reverse crunches.
Hanging Knee Raises - How to Do Them

• Start by grabbing a hold of a pull bar.
  
• Keep your body straight.
  
• Then lift your knees up to just about touch your chest.
  
• Avoid swinging as that can screw up the motion.
  

Between lifting weights with compound exercises and doing effective ab exercises like hanging knee raises you should have no problem getting abs.
But what about proper dieting?