Near the end of the level, you’ll see a Koopa Troopa walking on top of lots of bricks. Star Coin 3: The final Star Coin requires speed and timing. If you’re having trouble reaching it, leave a few coins in place to turn back into bricks once the P Switch wears off, then use the bricks as a platform to reach the Star Coin. Hit the switch so the Goombas fall to the ground, then jump on them to boost yourself up to the Star Coin. Take out the Koopa Troopa, then take the pipe to a room where you’ll see bricks, giant Goombas, a P Switch, and the Star Coin. Next to this is a giant Koopa Troopa on a regular-sized pipe. Star Coin 2: Past the checkpoint, you’ll come to a small platform with an arrow signpost on it. Knock it out and send its shell flying - it will break the bricks, giving you access to the Star Coin. At the top of the platforms is a giant Koopa Troopa.

Star Coin 1: You’ll see the first Star Coin at the bottom of a series of three platforms, seemingly blocked off by bricks you can’t break.

Super mario bros world 7-4 star coins