I'm trying 2 find a coin on super mario bros DS

To unlock world 4 you must
Beat the boss in the last castle of World 2 as Mini Mario.
and to unlock world 7 you must
Defeat the World 5 Castle Boss as Mini Mario or unlock the World 4 Cannon (you need to finish the W4 haunted house with a RED FLAG)

Here is a star coin location guide to help you with all those tricky to get star coins. <br> http://www.gamefaqs.com/portable/ds/file/920787/43215 <br> I hope this helps!

WHat you do is do not hit the 1st red button, then hit the second red button and then dont hit any more red buttons

THERE IS A HIDDEN ICON HIDDEN IN WALL HALFWAY THRU.

HERE IS THE WALKTHROUGH HOIPE IT HELPS

http://www.gamefaqs.com/portable/ds/file/920787/43152

Beat World 8 Castle 2 and then u will head on to BOWSER's CASTLE

defeat sand worm in last castle in world 2 with mini mario by jumping on it's head with a **** drop then you'll fall through the crack to world 4'''

you haf to get to beat the bosses in world 2 & 5 with mini mario. or beat the boss in world 2 as mini mario, and do it 2 world 4 as well 2 save time.

the last long rope before the cement platforms when you get to bowsers dore.... stand in the middle of the long rope and bounce up..... you will see a green tube, and it takes you up to the last coin....

Watch this walkthrough and do what this player does...I won the game with this walkthrough but play it EXACTLY like he does...

http://www.youtube.com/watch?v=b39vSV0HFI4