There is a natural number which when added to a natural number, gives the number itself.
Step 1: In this book, natural numbers are 1, 2, 3, ... (that is, \(0\) is not counted as a natural number).
Step 2: We are looking for a natural number \(k\) such that adding it does not change any number.
That means: \(n + k = n\) for natural numbers \(n\).
Step 3: Try \(n = 1\).
Then: \(1 + k = 1\).
So: \(k = 0\).
Step 4: But \(0\) is not a natural number here.
Conclusion: There is no natural number with this property. So the statement is false.