Write the divisor outside and the dividend inside a long-division bracket.
Divide the first part of the dividend (enough digits to be at least as large as the divisor) by the divisor.
Write the quotient digit at the top above that part.
Multiply the quotient digit by the divisor.
Subtract the result from the part of the dividend.
Bring down the next digit of the dividend.
Repeat: divide, multiply, subtract, and bring down.
When the subtraction result is 0, stop and write the quotient.
If the last remainder is not 0, write the remainder after a slash (remainder/divisor) or as a decimal by adding a decimal point and bringing down zeros.