Put students in pairs. Each pair has one basketball. Student A dribbles from one end line to the other end line. Student B runs next to Student A. It is a race between the 2, one is dribbling the other is not. If your gym is big enough, every student in the class can participate at the same time. If not, half of the pairs can go at a time. Do the race twice, so each student gets an opportunity to be the dribbler.
After the races, call them in for a brief discussion. In most cases, the non-dribbler was able to keep up with or beat the dribbler in a race. Tell them they are now going to race a very difficult opponent - THE BALL!
Have all of the students line up on an end line. They will run to the other end line on the command "GO". The teacher stands on the start line with the ball. No students have basketballs. The teacher says "GO". The students run. The teacher throws the ball towards the finish line. The ball wins every time.
After the race, call them in for another discussion. Explain to them that many people can keep up with or go faster than someone who is dribbling, but nobody can keep up with or beat a thrown ball. Tell them that they are going to play basketball now. Start in smaller sided games if you wish.
Make teams and put them on the court with a "flat" ball. This will assure that they pass the ball. Only use the flat ball for a short while to prove the point about emphasizing the importance of passing (instead of dribbling) when your team is on offense. When you finally let them use an inflated ball, observe the number of passes. It should increase.