how do you turn a fraction into a decimal
To turn a fraction into a decimal, you divide the top number by the bottom number: numerator ÷ denominator.
The core idea (super short)
- Take a fraction like 34\frac{3}{4}43.
- Do the division: 3÷4=0.753÷4=0.753÷4=0.75.
- That answer (0.75) is the decimal form of the fraction.
Step‑by‑step method (long division)
Use this when the numbers don’t divide evenly in your head.
- Write the fraction as a division:
- ab\frac{a}{b}ba means a÷ba÷ba÷b.
- Example: 18=1÷8\frac{1}{8}=1÷881=1÷8.
- If the top number (numerator) is smaller than the bottom number (denominator), add a decimal and a zero:
- 1 ÷ 8 becomes 1.0 ÷ 8.
- You now divide 10 by 8 (because of the 0 after the decimal).
- Do long division:
- 8 goes into 10 one time → write 0.1 so far.
- Remainder is 2 (because 10 − 8 = 2).
- Bring down another 0 → now you divide 20 by 8.
- 8 goes into 20 two times → write 0.12.
- Remainder is 4 (20 − 16 = 4).
- Bring down another 0 → divide 40 by 8.
- 8 goes into 40 five times → write 0.125.
- Remainder is 0, so you’re done: 18=0.125\frac{1}{8}=0.12581=0.125.
You can stop when:
- The remainder becomes 0 (it terminates), or
- You see a pattern repeating (like 0.3333…) and write it as a repeating decimal (often with a bar on top in school).
Shortcut when the denominator is 10, 100, 1000…
If the bottom of the fraction is a power of 10 (10, 100, 1000, …), you don’t need long division.
- 710=0.7\frac{7}{10}=0.7107=0.7 (one zero → one digit after the decimal).
- 34100=0.34\frac{34}{100}=0.3410034=0.34 (two zeros → two digits after the decimal).
- 8751000=0.875\frac{875}{1000}=0.8751000875=0.875 (three zeros → three digits after the decimal).
So: count the zeros in the denominator; that’s how many digits go after the decimal.
Trick to make the denominator a power of 10
Sometimes you can turn a “nice” fraction into tenths, hundredths, or thousandths. Example: 78\frac{7}{8}87
- Ask: what can I multiply 8 by to get 100 or 1000?
- 8 × 125 = 1000.
- Multiply top and bottom by the same number:
- 78=7×1258×125=8751000\frac{7}{8}=\frac{7×125}{8×125}=\frac{875}{1000}87=8×1257×125=1000875.
- Now use the power‑of‑10 trick:
- 8751000=0.875\frac{875}{1000}=0.8751000875=0.875.
Mixed numbers (like 2 ½)
If you have a mixed fraction, convert the fraction part , then add the whole number. Example: 2142\frac{1}{4}241
- Convert 14\frac{1}{4}41 to decimal:
- 1 ÷ 4 = 0.25.
- Add the whole number:
- 2 + 0.25 = 2.25.
So 214=2.252\frac{1}{4}=2.25241=2.25.
Quick mental examples
- 12=0.5\frac{1}{2}=0.521=0.5
- 14=0.25\frac{1}{4}=0.2541=0.25
- 34=0.75\frac{3}{4}=0.7543=0.75
- 15=0.2\frac{1}{5}=0.251=0.2
- 25=0.4\frac{2}{5}=0.452=0.4
- 35=0.6\frac{3}{5}=0.653=0.6
These are worth memorizing because they show up a lot.
TL;DR
- Write the fraction as a division: numerator ÷ denominator.
- Use long division if it doesn’t come out evenly.
- If the denominator is 10, 100, 1000, just place the decimal point according to the zeros.
- For mixed numbers, convert the fraction part and add it to the whole number.
If you tell me a specific fraction you’re stuck on, I can walk through that exact one with you.