Misconception 1: The 'Bigger' Digit is Always More Valuable
A student might see the number 29 and think 9 is more valuable than 2 because it's a larger digit. The correct understanding is that the 2 is in the tens place, giving it a value of 20, which is much greater than the 9 in the ones place.
Misconception 2: Confusion with Decimals
The place values to the right of the decimal point are a mirror image of those on the left, but without a 'oneths' place. The first place after the decimal is the 'tenths', not the 'oneths'. For example, in 1.1, the first '1' is one, and the second '1' is one-tenth.
Correct Method: The Role of Zero
Zero is a critical placeholder. In the number 408, the zero holds the tens place, indicating that there are no tens. Without it, the number would be 48, a completely different value. The zero ensures that the 4 is understood to be in the hundreds place.