Compare the entropy of a firecracker before it is lighted to its entropy after it explodes

The entropy of a firecracker is much less before it explodes than afterwards.

Entropy is a measure of the degree of disorder in a system.

Before the explosion, everything is packed in a small volume inside a cardboard tube.

After the explosion, the contents have been converted largely to gases and finely divided solids spread over a large volume of the sky.

The latter situation is more disordered, so it has a higher entropy.