What is 9/21 plus 11/21?
9/21 plus 11/21 equals 20/21 (or 0.952381 in decimal form). Learn the step-by-step solution to add 9/21 and 11/21 using Least Common Denominator and simplification.
Exact Answer
9/21 + 11/21 = 20/21
Simplified Fraction
20/21
Mixed Number
Proper (20/21)
Decimal Value
0.952381
Percentage
95.2381%
Step-by-Step Solution: 9/21 + 11/21
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.
9/21 + 11/21
Step 2
Add the Numerators
Now add the numerators (9 + 11 = 20) and keep the common denominator 21 unchanged.
9 + 11/21 = 20/21
Step 3
Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 20 and 21 is 1, confirming that 20/21 cannot be reduced further—it is already in its simplest irreducible form.
20/21
Step 4
Decimal & Percentage Representation
Dividing the numerator 20 by denominator 21 produces a repeating decimal (approximately 0.952381, or 95.2381%).
20 ÷ 21 = 0.952381 (95.2381%)
Visual Representation
The diagram below illustrates 9/21 plus 11/21 visually:
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Summary & Alternative Representations
| Property / Format | Value |
|---|---|
| Lowest Terms Fraction | 20/21 |
| Mixed Number Form | 20/21 |
| Decimal Form | 0.952381 |
| Percentage | 95.2381% |
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Frequently Asked Questions
What is 9/21 plus 11/21 as a fraction?
9/21 + 11/21 in simplest fraction form is 20/21.
What is 9/21 plus 11/21 as a decimal?
9/21 + 11/21 converted to a decimal is 0.952381.
What is 9/21 plus 11/21 as a percentage?
9/21 + 11/21 expressed as a percentage is 95.2381%.
Does 9/21 plus 11/21 result in a terminating or repeating decimal?
It results in a repeating decimal (approximately 0.952381...) because the denominator contains prime factors other than 2 and 5.