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Greatest Common Divisor (GCD) of 147 and 42

The greatest common divisor (GCD) of 147 and 42 is 21.

What is the Greatest Common Divisor (GCD)?

The GCD of two integers is the largest positive integer that divides both numbers without leaving a remainder. It is useful in simplifying fractions, finding common factors, and in number theory.

How to Calculate the GCD of 147 and 42?

We use the Euclidean algorithm, which involves the following steps:

  1. Divide the larger number by the smaller number.
  2. Replace the larger number with the smaller number and the smaller number with the remainder from the division.
  3. Repeat this process until the remainder is zero.
  4. The non-zero remainder just before zero is the GCD.

Step-by-Step Euclidean Algorithm

StepCalculation
1 147 ÷ 42 = 3 remainder 21
2 42 ÷ 21 = 2 remainder 0

Examples of GCD Calculations

NumbersGCD
122 and 262
94 and 1502
166 and 251
32 and 1091
103 and 881

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