What is 1/21 plus 4/21? (Answer: 5/21)

Exact Answer

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Problem: What is 1/21 plus 4/21?
Formula / Expression: 1/21 + 4/21
Final Answer: 5/21
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Step-by-Step Solution:

Step 1: Check the Denominators (Like Fractions)
Both fractions already share the identical denominator (21). Because these are like fractions, no conversion to a common denominator is required—we directly add their numerators while keeping the denominator 21.
Working: 1/21 + 4/21

Step 2: Add the Numerators
Now add the numerators (1 + 4 = 5) and keep the common denominator 21 unchanged.
Working: 1 + 4/21 = 5/21

Step 3: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 5 and 21 is 1, confirming that 5/21 cannot be reduced further—it is already in its simplest irreducible form.
Working: 5/21

Step 4: Decimal & Percentage Representation
Dividing the numerator 5 by denominator 21 produces a repeating decimal (approximately 0.238095, or 23.8095%).
Working: 5 ÷ 21 = 0.238095 (23.8095%)

Key Values:
- Simplified Fraction: 5/21
- Mixed Number Form: 5/21
- Decimal Value: 0.238095
- Percentage: 23.8095%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-1-21-plus-4-21/
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1/21 + 4/21 = 5/21

Simplified Fraction

5/21

Mixed Number

Proper (5/21)

Decimal Value

0.238095

Percentage

23.8095%

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Step-by-Step Solution: 1/21 + 4/21

Step 1

Check the Denominators (Like Fractions)

Both fractions already share the identical denominator (21). Because these are like fractions, no conversion to a common denominator is required—we directly add their numerators while keeping the denominator 21.

1/21 + 4/21

Step 2

Add the Numerators

Now add the numerators (1 + 4 = 5) and keep the common denominator 21 unchanged.

1 + 4/21 = 5/21

Step 3

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 5 and 21 is 1, confirming that 5/21 cannot be reduced further—it is already in its simplest irreducible form.

5/21

Step 4

Decimal & Percentage Representation

Dividing the numerator 5 by denominator 21 produces a repeating decimal (approximately 0.238095, or 23.8095%).

5 ÷ 21 = 0.238095 (23.8095%)

Visual Representation

The diagram below illustrates 1/21 plus 4/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`5/21`
Mixed Number Form	`5/21`
Decimal Form	`0.238095`
Percentage	`23.8095%`

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Frequently Asked Questions

What is 1/21 plus 4/21 as a fraction?

1/21 + 4/21 in simplest fraction form is 5/21.

What is 1/21 plus 4/21 as a decimal?

1/21 + 4/21 converted to a decimal is 0.238095.

What is 1/21 plus 4/21 as a percentage?

1/21 + 4/21 expressed as a percentage is 23.8095%.

Does 1/21 plus 4/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.238095...) because the denominator contains prime factors other than 2 and 5.