Long division calculator that shows every step: quotient and remainder, the decimal quotient with its repeating block marked, and the fraction.
更新于 已验证的示例：8
1,234 ÷ 7 = 176.(285714); the block 285714 repeats forever. The whole-number answer is 176 R 2, or 176 2/7 as a mixed number.
| Step | Partial dividend | Quotient digit | Place | × 7 | Remainder |
|---|---|---|---|---|---|
| 1 | 12 | 1 | hundreds | 7 | 5 |
| 2 | 53 | 7 | tens | 49 | 4 |
| 3 | 44 | 6 | ones | 42 | 2 |
| 4 | 20 | 2 | tenths | 14 | 6 |
| 5 | 60 | 8 | hundredths | 56 | 4 |
| 6 | 40 | 5 | thousandths | 35 | 5 |
| 7 | 50 | 7 | ten-thousandths | 49 | 1 |
| 8 | 10 | 1 | hundred-thousandths | 7 | 3 |
| 9 | 30 | 4 | millionths | 28 | 2 |
Each line divides the current partial dividend by 7; the remainder, with the next digit brought down, starts the next line.
Multiply back and add the remainder to check the division.
The remainder came back 6 digits later, so the digits under the bar repeat forever.
Long division splits a division into one small division per digit. Take the leading digits of the dividend, divide by the divisor, write the digit above, multiply, subtract, then bring down the next digit and repeat. When the divisor has decimals, both numbers are first multiplied by the same power of 10 so the divisor is a whole number.
For 1234 ÷ 7 the working gives 176 with remainder 2, since 7 × 176 = 1232. Carrying on past the decimal point with appended zeros gives 176.285714…, and because the remainder 2 comes back after six more digits, the block 285714 repeats forever. The layout marks that block with a bar.
A fraction's decimal either ends or repeats. It ends when the reduced denominator has no prime factors other than 2 and 5, as with 487 ÷ 32 = 15.21875. Otherwise the length of the repeating block is the smallest k for which 10ᵏ − 1 is divisible by q once its factors of 2 and 5 are removed: 6 for q = 7 and 96 for q = 97.
核验来源：Python 3.8: divmod(1234, 7) = (176, 2); decimal.Decimal(1234) / 7 = 176.28571428571428571…; Fraction(1234, 7) = 1234/7
核验来源：Calculator Soup long division tutorial: 487 ÷ 32 = 15 R 7; 487/32 = 15.21875 by Python Fraction
核验来源：Omni Calculator long division page: 65321 / 31 = 2107 r 4; period of 1/31 is 15 (ord₃₁ 10 = 15, Python pow(10, 15, 31) == 1)
核验来源：Calculator Soup long division with decimals example (4.71 ÷ 3.2 = 1.471… to 3 places); exact 471/320 = 1.471875 and 4.71 − 3.2 = 1.51 by Python Fraction
Repeat four moves: divide, multiply, subtract, bring down. For 487 ÷ 32: 48 ÷ 32 = 1, write 1, 1 × 32 = 32, 48 − 32 = 16; bring down 7 to make 167; 167 ÷ 32 = 5, 5 × 32 = 160, 167 − 160 = 7. No digits are left, so 487 ÷ 32 = 15 remainder 7. Check it: 32 × 15 + 7 = 487.
Move the decimal point in the divisor to the right until it is a whole number, and move the point in the dividend the same number of places. For 4.71 ÷ 3.2, move both one place: 47.1 ÷ 32. The quotient stays the same because both numbers were multiplied by 10. Then divide as usual, putting the quotient's point directly above the dividend's: 47.1 ÷ 32 = 1.471875.
As a fraction, put the remainder over the divisor: 1234 ÷ 7 = 176 R 2 = 176 2/7. As a decimal, keep dividing: write a decimal point and zeros after the dividend and bring them down one at a time. 2/7 = 0.285714285714…, so 1234 ÷ 7 = 176.285714…, where the six digits 285714 repeat.
Watch the remainders. Once only appended zeros are being brought down, each step depends only on the current remainder, and there are fewer possible remainders than the divisor. As soon as a remainder appears a second time, the digits between the two appearances repeat forever. Dividing by 7 always repeats within 6 digits; 1 ÷ 97 has a 96-digit repeating block.
It depends on the convention. This page divides the absolute values and gives the remainder the dividend's sign, as C and Java do: −17 ÷ 5 = −3 R −2, since 5 × (−3) − 2 = −17; Excel's QUOTIENT truncates to −3 the same way. The floored convention used by Python's // and % and by Excel's MOD gives −4 R 3 instead, since 5 × (−4) + 3 = −17.
准确性取决于输入值和方法的假设。十进制运算使用50位有效数字，但估算、数值方法和源数据的精度可能较低；显示时的舍入并不能消除这些限制。 已按独立来源核验的计算示例：8。 例如，“1234 ÷ 7 (default)”根据Python 3.8: divmod(1234, 7) = (176, 2); decimal.Decimal(1234) / 7 = 176.28571428571428571…; Fraction(1234, 7) = 1234/7进行核验。
Common Core State Standards for Mathematics, 6.NS.B.2 and 6.NS.B.3: divide multi-digit numbers and decimals using the standard algorithm; Hardy & Wright, An Introduction to the Theory of Numbers, §9.6 (period of a recurring decimal is the order of 10 modulo q); Wolfram MathWorld: Long division; Wolfram MathWorld: Repeating decimal.
此计算器包含 8 个已解示例，答案来自独立来源。这些示例会在测试套件中运行，你也可以在此运行验证。
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