Decimal places have place value with respect to the decimal point, the same as integer places to the left of the decimal point. This picture shows a few of them.

Just as you would say 432,000 represents 432 thousands, 432*1000, you can say .432 represents 432 thousandths, 432/1000.

432/1000 is your fraction for .432. This example can be reduced to lower terms by dividing numerator and denominator by 8: .432 = 54/125.

A mixed number works as you would expect.

10.8 = 10 8/10 = 10 4/5

Just as you would say 432,000 represents 432 thousands, 432*1000, you can say .432 represents 432 thousandths, 432/1000.

432/1000 is your fraction for .432. This example can be reduced to lower terms by dividing numerator and denominator by 8: .432 = 54/125.

A mixed number works as you would expect.

10.8 = 10 8/10 = 10 4/5