Example 2:

To compare decimals with the different place values:

Juan’s fish tank has 15.4 gallons of water.
Mark’s fish tank has 15.45 gallons of water.
Sean’s fish tank has 15.405 gallons of water.

• Since all of the decimals have the same whole number (15), compare the digits to the right of the decimal point.

15.4                15.45              15.405

• Since one of the decimals ends in the thousandths place, rewrite all three decimals in thousandths. Change the place value of decimals by adding zeros after the last digit until all decimals are to the same place value.

15.400            15.450            15.405

• Now compare 400 thousandths, 450 thousandths, and 405 thousandths. Since 450 thousandths is greater than 405 thousandths and 405 thousandths is greater than 400 thousandths,

15.450 > 15.405 > 15.400