Long division is a method for dividing large numbers by breaking the process into a sequence of smaller, easier steps. You repeatedly divide, multiply, subtract, and bring down digits until you reach the quotient.
In integer division, the remainder is what is left over after the dividend is divided as many whole times as possible by the divisor. For example, 487 ÷ 13 = 37 remainder 6 (because 37 × 13 + 6 = 487).