Find it in the mushaf: Surah Sad is surah 38. Find ayah 42. The key word mughtasal means a place for washing. Allah answered Ayyub's du'a with a spring of cool water. He washed and drank, and Allah healed him. Much of the fresh water on Earth is hidden underground and comes up as springs. It is a sign to ponder: Allah sends cure and help in ways we do not expect.
Fact: Roughly what share of the Earth's fresh liquid water is stored underground?
Ages 5–8: Spring in a cup. Push a sponge into a cup of water and watch water rise up around it.
Ages 9–12: Water journey. Draw how rain soaks into the ground and comes out as a spring.
Finish with: "I found that about ___ of fresh liquid water is underground."