Definition
Decimal place value
Decimal place value is the value a digit has because of its position relative to the decimal point.
What it means
Use the decimal point as a landmark. Whole-number places are to its left. Tenths, hundredths, thousandths, and smaller places are to its right. The same digit can name very different amounts depending on its place: 4 tenths is ten times 4 hundredths.
Remember it
One place left is ten times as much; one place right is one tenth as much.
Example
In 6.407, the 6 means 6 ones, the 4 means 4 tenths, the 0 means 0 hundredths, and the 7 means 7 thousandths. So 6.407 = 6 + 0.4 + 0 + 0.007.
Watch for
The decimal point separates the ones place from the tenths place; it is a fixed landmark, not a digit with its own value.
Common mix-up
0.4 and 0.04 do not have the same value. The 4 in 0.4 is in the tenths place, while the 4 in 0.04 is in the hundredths place.
Exact meaning
Decimal place value is the value a digit has from its position relative to the decimal point. Each place is ten times the value of the place immediately to its right and one tenth the value of the place immediately to its left.