The exercise demonstrates how to create a summary by removing unnecessary details. Here's a clearer breakdown:

**Step 1: Read the text. Cross out the sentences that are not important.**
- Aladdin lived with his mother. ~~Their house was old.~~ One day, an old man came to the town. ~~He was new in the town. He walked slowly down the road.~~ The old man said, 'Aladdin, I'm your uncle.'

**Step 2: Write the text.**
- Aladdin lived with his mother. One day, an old man came to the town. The old man said, 'Aladdin, I'm your uncle.'

The summary retains the essential information: Aladdin's living situation and the arrival of the old man who claims to be his uncle.