Ctrl+k

Relate decimals and mixed numbers

A terminating decimal can be interpreted as a whole-number part plus a fractional part with a denominator based on powers of ten, and represented equivalently as a mixed number; the reverse conversion preserves the same quantity. Place value and number-line representations clarify relationships such as 4.35=435100=47204.35=4\frac{35}{100}=4\frac{7}{20}, avoiding the misconception that decimal digits form a numerator independently of their place value. Nonterminating-decimal conversions are outside this scope.

Detailed Explanation: Relate decimals and mixed numbers

A terminating decimal has a whole-number part and a fractional part.

To change a decimal to a mixed number:

  1. Keep the digits to the left of the decimal point as the whole-number part.
  2. Write the digits to the right of the decimal point as a fraction.
  3. Use a denominator based on the place value:
    • tenths 10\rightarrow 10
    • hundredths 100\rightarrow 100
    • thousandths 1000\rightarrow 1000
  4. Simplify the fraction if possible.

Example: Write 4.354.35 as a mixed number.

The whole-number part is 44.

The digits 3535 are in the hundredths place, so the fractional part is 35100\frac{35}{100}:

4.35=4351004.35=4\frac{35}{100}

Now simplify 35100\frac{35}{100}. Both 3535 and 100100 can be divided by 55:

35100=720\frac{35}{100}=\frac{7}{20}

Therefore,

4.35=4720\boxed{4.35=4\frac{7}{20}}

The denominator is 100100 before simplifying because 0.350.35 means 3535 hundredths. The digits do not form a fraction by themselves; their place value tells you the denominator.

To check the reverse conversion, convert 720\frac{7}{20} to hundredths:

720=35100=0.35\frac{7}{20}=\frac{35}{100}=0.35

So 47204\frac{7}{20} and 4.354.35 represent the same quantity.

Learn by doing: Relate decimals and mixed numbers

Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill

Practice with unlimited practice problems

Decimals to Fractions - Standard


    ?