What is 3/21 plus 5/21? (Answer: 8/21)

Exact Answer

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Problem: What is 3/21 plus 5/21?
Formula / Expression: 3/21 + 5/21
Final Answer: 8/21
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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: 3/21 + 5/21

Step 2: Add the Numerators
Now add the numerators (3 + 5 = 8) and keep the common denominator 21 unchanged.
Working: 3 + 5/21 = 8/21

Step 3: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 8 and 21 is 1, confirming that 8/21 cannot be reduced further—it is already in its simplest irreducible form.
Working: 8/21

Step 4: Decimal & Percentage Representation
Dividing the numerator 8 by denominator 21 produces a repeating decimal (approximately 0.380952, or 38.0952%).
Working: 8 ÷ 21 = 0.380952 (38.0952%)

Key Values:
- Simplified Fraction: 8/21
- Mixed Number Form: 8/21
- Decimal Value: 0.380952
- Percentage: 38.0952%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-3-21-plus-5-21/
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3/21 + 5/21 = 8/21

Simplified Fraction

8/21

Mixed Number

Proper (8/21)

Decimal Value

0.380952

Percentage

38.0952%

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Step-by-Step Solution: 3/21 + 5/21

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.

3/21 + 5/21

Step 2

Add the Numerators

Now add the numerators (3 + 5 = 8) and keep the common denominator 21 unchanged.

3 + 5/21 = 8/21

Step 3

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 8 and 21 is 1, confirming that 8/21 cannot be reduced further—it is already in its simplest irreducible form.

8/21

Step 4

Decimal & Percentage Representation

Dividing the numerator 8 by denominator 21 produces a repeating decimal (approximately 0.380952, or 38.0952%).

8 ÷ 21 = 0.380952 (38.0952%)

Visual Representation

The diagram below illustrates 3/21 plus 5/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`8/21`
Mixed Number Form	`8/21`
Decimal Form	`0.380952`
Percentage	`38.0952%`

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Frequently Asked Questions

What is 3/21 plus 5/21 as a fraction?

3/21 + 5/21 in simplest fraction form is 8/21.

What is 3/21 plus 5/21 as a decimal?

3/21 + 5/21 converted to a decimal is 0.380952.

What is 3/21 plus 5/21 as a percentage?

3/21 + 5/21 expressed as a percentage is 38.0952%.

Does 3/21 plus 5/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.380952...) because the denominator contains prime factors other than 2 and 5.