What is 3/21 plus 7/21?
3/21 plus 7/21 equals 10/21 (or 0.47619 in decimal form). Learn the step-by-step solution to add 3/21 and 7/21 using Least Common Denominator and simplification.
Exact Answer
3/21 + 7/21 = 10/21
Simplified Fraction
10/21
Mixed Number
Proper (10/21)
Decimal Value
0.47619
Percentage
47.619%
Step-by-Step Solution: 3/21 + 7/21
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 + 7/21
Step 2
Add the Numerators
Now add the numerators (3 + 7 = 10) and keep the common denominator 21 unchanged.
3 + 7/21 = 10/21
Step 3
Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 10 and 21 is 1, confirming that 10/21 cannot be reduced further—it is already in its simplest irreducible form.
10/21
Step 4
Decimal & Percentage Representation
Dividing the numerator 10 by denominator 21 produces a repeating decimal (approximately 0.47619, or 47.619%).
10 ÷ 21 = 0.47619 (47.619%)
Visual Representation
The diagram below illustrates 3/21 plus 7/21 visually:
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Summary & Alternative Representations
| Property / Format | Value |
|---|---|
| Lowest Terms Fraction | 10/21 |
| Mixed Number Form | 10/21 |
| Decimal Form | 0.47619 |
| Percentage | 47.619% |
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Frequently Asked Questions
What is 3/21 plus 7/21 as a fraction?
3/21 + 7/21 in simplest fraction form is 10/21.
What is 3/21 plus 7/21 as a decimal?
3/21 + 7/21 converted to a decimal is 0.47619.
What is 3/21 plus 7/21 as a percentage?
3/21 + 7/21 expressed as a percentage is 47.619%.
Does 3/21 plus 7/21 result in a terminating or repeating decimal?
It results in a repeating decimal (approximately 0.47619...) because the denominator contains prime factors other than 2 and 5.