The missing-sock hunt
Your laundry comes out with one sock missing, so you retrace every step to find where it vanished. Debugging is that same hunt in code — following the program's steps until you catch the exact spot where things went wrong.
A bug is just a mistake
When a program doesn't do what we wanted, there's a bug — a mistake in the steps. Good coders don't panic; they read the blocks one at a time and pretend to be the computer, doing exactly what each block says.
Be the computer
Trace through the steps slowly, in order. The place where what-you-expected and what-happens split apart is where the bug hides.
Blocks say: 'jump' then 'put on shoes'. The character jumps barefoot! Swap the order: 'put on shoes' then 'jump'.