Place Value Problem: Identifying 3 in the Tens Position

3 is the tens digit in which number?

To solve this problem, let's investigate the place value system, specifically focusing on the tens digit:

In a two-digit number, the tens place is the second position from the right. Therefore, the number 35 can be deconstructed as follows:

• The tens digit is '3'.
• The units (or ones) digit is '5'.

Our task is to find which number among the given choices has '3' as its tens digit.

Let's break down each option:

• Option 1: $13$ – The tens digit is '1'.
• Option 2: $23$ – The tens digit is '2'.
• Option 3: $31$ – The tens digit is '3'.
• Option 4: $43$ – The tens digit is '4'.

The number that has '3' as the tens digit is clearly $31$.

Therefore, the solution to the problem is $31$.