What is 1/5 plus 1/2?
1/5 plus 1/2 equals 7/10 (or 0.7 in decimal form). Learn the step-by-step solution to add 1/5 and 1/2 using Least Common Denominator and simplification.
Exact Answer
1/5 + 1/2 = 7/10
Simplified Fraction
7/10
Mixed Number
Proper (7/10)
Decimal Value
0.7
Percentage
70%
Step-by-Step Solution: 1/5 + 1/2
Step 1
Find the Least Common Denominator (LCD)
The denominators 5 and 2 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 5 × 2 = 10.
LCD(5, 2) = 10
Step 2
Convert to Equivalent Fractions with Common Denominator 10
Multiply the numerator and denominator of 1/5 by 2, and multiply the numerator and denominator of 1/2 by 5 so both fractions share the common base 10.
1 × 2/5 × 2 = 2/10 and 1 × 5/2 × 5 = 5/10
Step 3
Add the Numerators
Now add the numerators (2 + 5 = 7) and keep the common denominator 10 unchanged.
2 + 5/10 = 7/10
Step 4
Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 7 and 10 is 1, confirming that 7/10 cannot be reduced further—it is already in its simplest irreducible form.
7/10
Step 5
Decimal & Percentage Representation
Dividing the numerator 7 by denominator 10 yields an exact terminating decimal of 0.7 (or 70%).
7 ÷ 10 = 0.7 (70%)
Visual Representation
The diagram below illustrates 1/5 plus 1/2 visually:
+
=
Summary & Alternative Representations
| Property / Format | Value |
|---|---|
| Lowest Terms Fraction | 7/10 |
| Mixed Number Form | 7/10 |
| Decimal Form | 0.7 |
| Percentage | 70% |
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Frequently Asked Questions
What is 1/5 plus 1/2 as a fraction?
1/5 + 1/2 in simplest fraction form is 7/10.
What is 1/5 plus 1/2 as a decimal?
1/5 + 1/2 converted to a decimal is 0.7.
What is 1/5 plus 1/2 as a percentage?
1/5 + 1/2 expressed as a percentage is 70%.
Does 1/5 plus 1/2 result in a terminating or repeating decimal?
It results in an exact terminating decimal (0.7) because the denominator in simplest terms contains only prime factors 2 and/or 5.