Question
If the counting numbers 1 to 30 are written down, how many times does the digit 2 appear?
13
11
12
14
13
11
12
14
Answers
GPT-4o mini
To find out how many times the digit '2' appears in the counting numbers from 1 to 30, we can break the problem down by examining the occurrences of '2' in each digit place (tens and units).
**Counting occurrences in the unit place (1 to 30):**
- The numbers that have '2' in the units place are: 2, 12, 22.
- This contributes 3 occurrences of '2'.
**Counting occurrences in the tens place (1 to 30):**
- The numbers that have '2' in the tens place are: 20, 21, 22, 23, 24, 25, 26, 27, 28, 29.
- This contributes 10 occurrences of '2' (one for each of these numbers).
Now, we can sum these occurrences:
- Occurrences from the unit place: 3
- Occurrences from the tens place: 10
Total occurrences = 3 + 10 = 13.
Therefore, the digit '2' appears **13 times** from the numbers 1 to 30.
The answer is **13**.
**Counting occurrences in the unit place (1 to 30):**
- The numbers that have '2' in the units place are: 2, 12, 22.
- This contributes 3 occurrences of '2'.
**Counting occurrences in the tens place (1 to 30):**
- The numbers that have '2' in the tens place are: 20, 21, 22, 23, 24, 25, 26, 27, 28, 29.
- This contributes 10 occurrences of '2' (one for each of these numbers).
Now, we can sum these occurrences:
- Occurrences from the unit place: 3
- Occurrences from the tens place: 10
Total occurrences = 3 + 10 = 13.
Therefore, the digit '2' appears **13 times** from the numbers 1 to 30.
The answer is **13**.