Writing Fractions as Decimal Numbers
Converting a fraction or mixed number to a decimal involves dividing the numerator by the denominator. In Grade 6 Saxon Math Course 1 (Chapter 8: Advanced Topics in Geometry and Number Operations), students keep the whole number portion unchanged and convert only the fractional part by dividing. For 5 3/5: the whole number 5 stays; divide 3 ÷ 5 = 0.6; combine to get 5.6. Some fractions produce terminating decimals (3/4 = 0.75) while others produce repeating decimals (1/3 = 0.333…). Students also convert common fractions from memory: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75.
Key Concepts
Contextual Explanation Mixed numbers have two parts: a whole number and a fraction. The whole number is already a champion—it gets to sit to the left of the decimal point without doing any work! Your only job is to convert the small fraction part into a decimal and let it join the whole number.
Full Example Problem : Write $8\frac{1}{4}$ as a decimal number.
Step 1: Identify the whole number part. For $8\frac{1}{4}$, the whole number is 8 . This will be the number to the left of the decimal point.
Common Questions
How do you convert a fraction to a decimal?
Divide the numerator by the denominator. For 3/8: 3 ÷ 8 = 0.375.
How do you convert a mixed number like 5 3/5 to a decimal?
Keep the whole number (5). Convert the fraction: 3 ÷ 5 = 0.6. Combine: 5.6.
What is a terminating decimal versus a repeating decimal?
A terminating decimal ends after a finite number of digits (e.g., 3/4 = 0.75). A repeating decimal has a digit or group that repeats forever (e.g., 1/3 = 0.333…).
What are some common fraction-to-decimal equivalences to memorize?
1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75, 1/5 = 0.2, 2/5 = 0.4, 1/10 = 0.1.
Why is converting fractions to decimals useful?
Decimals are easier to compare and to enter into calculators. Converting allows direct comparison of fractions and decimals, such as determining which is larger: 5/8 or 0.6.