A fraction is a division in disguise: to convert it to a decimal, divide the numerator by the denominator. 3/4 = 3 ÷ 4 = 0.75. When the denominator easily scales to 10, 100 or 1000 there's a shortcut — 7/20 = 35/100 = 0.35 — and some fractions, like 2/3 = 0.666…, produce repeating decimals you round or write with a bar.
3/4 literally means 3 ÷ 4. That single idea is the whole conversion — everything else is arithmetic technique.
Use short or long division, adding a decimal point and zeros to the numerator as needed: 3 ÷ 4 → 3.00 ÷ 4 = 0.75. A calculator does the same thing in one step.
If the denominator divides evenly into 10, 100 or 1000, multiply top and bottom to get there and read the decimal straight off: 7/20 = 35/100 = 0.35. This works for denominators like 2, 4, 5, 8, 20, 25 and 50 — but not 3, 6, 7 or 9.
If the division never ends, the digits repeat: 2/3 = 0.666… Write it with a bar over the repeating digit (0.6̄) or round to a stated number of places (0.67 to 2 d.p.). A fraction in simplest form terminates only when its denominator's prime factors are just 2s and 5s.
Divide top by bottom
Convert 3/4 to a decimal
Answer: 0.75
Scale to hundredths
Convert 7/20 to a decimal
Answer: 0.35
A repeating decimal
Convert 2/3 to a decimal
Answer: 0.666… (≈ 0.67)
3/4 is 3 ÷ 4 = 0.75, not 4 ÷ 3 = 1.33… If your decimal for a proper fraction comes out bigger than 1, you divided bottom by top.
7/20 = 35/100 = 0.35, not 0.035. The number of decimal places must match the power of ten: hundredths means exactly two places.
2/3 is not equal to 0.66 or 0.67 — those are approximations. Keep the fraction when you need an exact value, and only round at the final step of a calculation.
Use long or short division: divide the numerator by the denominator, adding a decimal point and zeros. 3/4 = 3.00 ÷ 4 = 0.75. If the denominator scales neatly to 10, 100 or 1000, that's usually faster: 7/20 = 35/100 = 0.35.
Worth knowing cold: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75, 1/5 = 0.2, 1/10 = 0.1, 1/8 = 0.125, 3/8 = 0.375, 1/3 ≈ 0.333 and 2/3 ≈ 0.667. Most everyday conversions are one of these or a simple multiple.
Write the fraction in simplest form and factorise the denominator. If it contains only 2s and 5s (like 4, 8, 10, 20, 25), the decimal terminates. Any other prime factor — 3, 7, 11 and so on — makes it repeat: 1/3 = 0.333…, 1/7 = 0.142857142857…
Write the digits over the matching power of ten and simplify: 0.35 = 35/100 = 7/20, and 0.75 = 75/100 = 3/4. The number of decimal places tells you the denominator.
Convert to a decimal, then multiply by 100: 3/4 = 0.75 = 75%. Or scale the fraction to hundredths directly — 3/4 = 75/100 — and read the percentage off the top.
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