Many students have some common misunderstandings about decimals and place value, which can lead to confusion. Here are a few of those I’ve seen:

1. Value of Digits: Some students think the digit "2" in $0.2$ is worth the same as the "2" in $2$. They don’t see how the place value changes its worth.

2. Decimal Size: A few might think that $0.1$ is bigger than $0.09$. It’s important to remember that when there are more digits after the decimal point, it can mean smaller numbers.

3. Adding Decimals: There’s often a mistake in how students line up the numbers. It’s really important to line up the decimal points first!

Understanding these points can really help clear up any confusion about decimals and place value!