How to convert a decimal to a fraction
- Write the decimal as a fraction with 1 in the denominator: e.g. 0.75/1.
- Multiply both numerator and denominator by 10 for each digit after the decimal point to get whole numbers.
- Simplify by dividing numerator and denominator by their GCD.
- If the result is an improper fraction, extract the whole part.
Example 1. Convert 0.75
- 2 decimal digits → multiply by 100: 75/100
- GCD(75, 100) = 25
- 75 ÷ 25 = 3, 100 ÷ 25 = 4
0.75 =
75
100
=
3
4
Example 2. Convert 1.375
- 3 decimal digits → multiply by 1000: 1375/1000
- GCD(1375, 1000) = 125
- 1375 ÷ 125 = 11, 1000 ÷ 125 = 8
- Extract whole part: 11/8 = 1 3/8
1.375 =
1375
1000
=
11
8
= 1
3
8
Example 3. Convert 3.6e6 (scientific notation)
- 3.6e6 = 3,600,000
- Write as 3600000/1 — already a whole number, no fraction part
3.6e6 = 3,600,000