In Super Mario ds how do you get to w7-8?

Ok

Hi

Well first you have to complete the world 6. Then you go to world eight. Then you must complete the HU-MON-GUS castle at the end. It's quite difficult. But anyway, if you do that (WELL DONE IF YOU DO, I had to get my brother to do it for me) You'll get world 7 and 4 (if you haven't unlocked that.)

OR

you have to complete the castle in world 6 as mini mario, and that's really hard.

Bye!

You don't get world 4 and 7 automatically when you finish the game. You have to beat the world 2 castle as Mini Mario to get world 4 and you do the the same except to world 5 to get world 7. World 4 is jungle themed and world 7 is sky themed. Have fun!