Find Thousandths in 1.123: Decimal Place Value Analysis

To solve this problem, we need to recognize the place value of the digits in the number 1.123.

In a decimal number, the positions to the right of the decimal point have specific place names:

• The first position is the tenths place.
• The second position is the hundredths place.
• The third position is the thousandths place.

Let's apply this understanding to the given number:

The number 1.123 can be broken down as:

• $1$ is the whole number,
• $0.1$ represents the tenths position,
• $0.02$ represents the hundredths position,
• $0.003$ represents the thousandths position.

This means that the third digit after the decimal, which is 3, represents the number of thousandths.

Therefore, in the number 1.123, there are 3 thousandths.

Thus, the correct answer is: 3.

This is represented by choice id "4".