Successor of a one digit number is always a one digit number.
Step 1: What is a successor?
The successor of a number is the number that comes just after it.
To find the successor, we add 1.
Step 2: One-digit numbers
Examples of one-digit numbers are 0, 1, 2, ..., 9.
Step 3: Try a counterexample
Take the largest one-digit number: 9.
Add 1 to get its successor:
\(9 + 1 = 10\)
The number 10 has two digits.
Step 4: Conclusion
Because at least one one-digit number (9) has a successor (10) that is not one-digit,
the statement is false.
Note: Some one-digit numbers like 3 have one-digit successors (\(3 + 1 = 4\)).
But the word “always” makes the statement wrong, since 9 is a counterexample.