Remainder

Definition

The remainder is the amount left over when one number is divided by another. It represents the part of the dividend that is not evenly divisible by the divisor, and it is always less than the divisor.

5 Must Know Facts For Your Next Test

1. The remainder is always a whole number, and it can be zero if the dividend is evenly divisible by the divisor.
2. The remainder can be used to determine the divisibility of a number, as a number is divisible by another if the remainder is zero.
3. In polynomial division, the remainder theorem states that the remainder when a polynomial $P(x)$ is divided by $(x - a)$ is $P(a)$.
4. The remainder can be used to simplify fractions, as the fraction can be expressed as a mixed number with the remainder as the numerator.
5. The remainder can be used to solve modular arithmetic problems, where the remainder represents the value of the expression modulo the divisor.

Review Questions

• Explain the relationship between the remainder and the divisibility of a number.
  • The remainder is directly related to the divisibility of a number. If the remainder is zero when a number is divided by another, then the first number is divisible by the second. This is because the dividend is evenly divisible by the divisor, leaving no leftover amount. Conversely, if the remainder is not zero, then the first number is not divisible by the second, and the remainder represents the part of the dividend that is not evenly divisible by the divisor.
• Describe how the remainder theorem is used in polynomial division.
  • The remainder theorem states that when a polynomial $P(x)$ is divided by $(x - a)$, the remainder is equal to $P(a)$. This means that the value of the polynomial at the point $x = a$ is the same as the remainder when the polynomial is divided by $(x - a)$. This theorem is useful in simplifying polynomial expressions and determining the factors of a polynomial.
• Analyze how the remainder can be used to solve modular arithmetic problems.
  • In modular arithmetic, the remainder plays a crucial role in determining the value of an expression modulo a given divisor. The remainder represents the value of the expression after it has been divided by the modulus, and this remainder is the only value that is considered relevant in modular arithmetic. By understanding the properties of the remainder, such as its relationship to divisibility and its behavior in polynomial division, students can effectively solve problems involving modular arithmetic, which is an important concept in various areas of mathematics, including cryptography and number theory.

Related terms

Dividend: The number being divided in a division operation.

Divisor: The number by which the dividend is being divided.

Quotient: The result of dividing the dividend by the divisor, representing the number of times the divisor goes into the dividend.