What is 7/21 plus 15/21?
7/21 plus 15/21 equals 22/21 (or 1 1/21 as a mixed number) (or 1.047619 in decimal form). Learn the step-by-step solution to add 7/21 and 15/21 using Least Common Denominator and simplification.
Exact Answer
7/21 + 15/21 = 22/21
Simplified Fraction
22/21
Mixed Number
1 1/21
Decimal Value
1.047619
Percentage
104.7619%
Step-by-Step Solution: 7/21 + 15/21
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.
7/21 + 15/21
Step 2
Add the Numerators
Now add the numerators (7 + 15 = 22) and keep the common denominator 21 unchanged.
7 + 15/21 = 22/21
Step 3
Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 22 and 21 is 1, confirming that 22/21 cannot be reduced further—it is already in its simplest irreducible form.
22/21
Step 4
Convert Improper Fraction to a Mixed Number
Since the numerator (22) is greater than the denominator (21), divide 22 by 21: it goes in 1 whole time(s) with a remainder of 1, giving the mixed number 1 1/21.
22/21 = 11/21
Step 5
Decimal & Percentage Representation
Dividing the numerator 22 by denominator 21 produces a repeating decimal (approximately 1.047619, or 104.7619%).
22 ÷ 21 = 1.047619 (104.7619%)
Visual Representation
The diagram below illustrates 7/21 plus 15/21 visually:
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Summary & Alternative Representations
| Property / Format | Value |
|---|---|
| Lowest Terms Fraction | 22/21 |
| Mixed Number Form | 1 1/21 |
| Decimal Form | 1.047619 |
| Percentage | 104.7619% |
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Frequently Asked Questions
What is 7/21 plus 15/21 as a fraction?
7/21 + 15/21 in simplest fraction form is 22/21 (or 1 1/21 as a mixed number).
What is 7/21 plus 15/21 as a decimal?
7/21 + 15/21 converted to a decimal is 1.047619.
What is 7/21 plus 15/21 as a percentage?
7/21 + 15/21 expressed as a percentage is 104.7619%.
How do you write 7/21 plus 15/21 as a mixed number?
Because the numerator is greater than the denominator, the improper fraction 22/21 can be written as the mixed number 1 1/21.
Does 7/21 plus 15/21 result in a terminating or repeating decimal?
It results in a repeating decimal (approximately 1.047619...) because the denominator contains prime factors other than 2 and 5.