Write 4.123 in expanded form

In expanded form, you will need to write out the ones place, tenths place, hundredths place, and thousandths place.
The answer is 4 + 0.1 + 0.02 + 0.003.

Okay. So when it comes to expanded form, we are talking about expanding it by place value and making it in the form of addition. The 4 in that number is just 4, the 1 is 0.1, the 2 is 0.02, and the 3 is 0.003. Those are the values. The number in expanded form is 4 + 0.1 + 0.02 + 0.003.