What is 11/21 plus 12/21?
11/21 plus 12/21 equals 23/21 (or 1 2/21 as a mixed number) (or 1.095238 in decimal form). Learn the step-by-step solution to add 11/21 and 12/21 using Least Common Denominator and simplification.
Exact Answer
11/21 + 12/21 = 23/21
Simplified Fraction
23/21
Mixed Number
1 2/21
Decimal Value
1.095238
Percentage
109.5238%
Step-by-Step Solution: 11/21 + 12/21
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.
11/21 + 12/21
Step 2
Add the Numerators
Now add the numerators (11 + 12 = 23) and keep the common denominator 21 unchanged.
11 + 12/21 = 23/21
Step 3
Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 23 and 21 is 1, confirming that 23/21 cannot be reduced further—it is already in its simplest irreducible form.
23/21
Step 4
Convert Improper Fraction to a Mixed Number
Since the numerator (23) is greater than the denominator (21), divide 23 by 21: it goes in 1 whole time(s) with a remainder of 2, giving the mixed number 1 2/21.
23/21 = 12/21
Step 5
Decimal & Percentage Representation
Dividing the numerator 23 by denominator 21 produces a repeating decimal (approximately 1.095238, or 109.5238%).
23 ÷ 21 = 1.095238 (109.5238%)
Visual Representation
The diagram below illustrates 11/21 plus 12/21 visually:
+
=
Summary & Alternative Representations
| Property / Format | Value |
|---|---|
| Lowest Terms Fraction | 23/21 |
| Mixed Number Form | 1 2/21 |
| Decimal Form | 1.095238 |
| Percentage | 109.5238% |
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Frequently Asked Questions
What is 11/21 plus 12/21 as a fraction?
11/21 + 12/21 in simplest fraction form is 23/21 (or 1 2/21 as a mixed number).
What is 11/21 plus 12/21 as a decimal?
11/21 + 12/21 converted to a decimal is 1.095238.
What is 11/21 plus 12/21 as a percentage?
11/21 + 12/21 expressed as a percentage is 109.5238%.
How do you write 11/21 plus 12/21 as a mixed number?
Because the numerator is greater than the denominator, the improper fraction 23/21 can be written as the mixed number 1 2/21.
Does 11/21 plus 12/21 result in a terminating or repeating decimal?
It results in a repeating decimal (approximately 1.095238...) because the denominator contains prime factors other than 2 and 5.