In New Super Mario Brothers for Nintendo DS, how do you get to World 4 and 7?

You have to beat the world 2 and world 5 bosses as Mini Mario, so here it goes:

Have a mini mushroom in your spare item area.

when you fight the bosses, change into mini Mario.

GROUND POUND instead of just jumping on them.

if you win, you'll head into world 4 or 7.

you should beat the boss of international 2 with the Mini Mario potential-as a lot as immediately fall right into a small hollow at the same time as leaving international 2. To defeat the cactus situation you should floor pound with Mini Mario. this can do the wear of one million familiar Mario bounce. similar situation with international 5 for international 7. Defeat Petey Piranha a similar way also.

Yes, perhaps the best way is google,you can try,may be you can solve this problem.