Simplest form answer

21/42 Simplified = 1/2

21/42 in simplest form is 1/2, found by dividing 21 and 42 by their greatest common factor, 21. As a decimal 1/2 is 0.5, and as a percent it is 50%.

Simplified

1/2

Decimal

0.5

Percent

50%

Step-by-step GCF reduction

1. Find the greatest common factor.

The GCF of 21 and 42 is 21.

2. Divide the numerator and denominator by the GCF.

21 ÷ 21 = 1

42 ÷ 21 = 2

3. Write the result.

21/42 simplified is 1/2.

Decimal and percentage equivalents

Decimal equivalent

1/2 = 0.5

Percentage equivalent

1/2 = 50%

Visual fraction bar

50%

The filled part represents 1/2 of one whole.

Cite this result

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21/42 in simplest form is 1/2, found by dividing 21 and 42 by their greatest common factor, 21.
ILoveFractions, https://www.ilovefractions.com/tools/fraction-simplifier/21-42/, retrieved September 2, 2026

APA

ILoveFractions. (2026). 21/42 Simplified = 1/2. ILoveFractions.com. Retrieved September 2, 2026, from https://www.ilovefractions.com/tools/fraction-simplifier/21-42/

MLA

"21/42 Simplified = 1/2." ILoveFractions.com, https://www.ilovefractions.com/tools/fraction-simplifier/21-42/. Accessed 2 September 2026.

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