What is 1/7 plus 2/8? (Answer: 11/28)

Exact Answer

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Problem: What is 1/7 plus 2/8?
Formula / Expression: 1/7 + 2/8
Final Answer: 11/28
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 7 and 8 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 7 × 8 = 56.
Working: LCD(7, 8) = 56

Step 2: Convert to Equivalent Fractions with Common Denominator 56
Multiply the numerator and denominator of 1/7 by 8, and multiply the numerator and denominator of 2/8 by 7 so both fractions share the common base 56.
Working: 1 × 8/7 × 8 = 8/56 and 2 × 7/8 × 7 = 14/56

Step 3: Add the Numerators
Now add the numerators (8 + 14 = 22) and keep the common denominator 56 unchanged.
Working: 8 + 14/56 = 22/56

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 22 and 56, which is 2. Divide both the numerator and denominator by 2.
Working: 22 ÷ 2/56 ÷ 2 = 11/28

Step 5: Decimal & Percentage Representation
Dividing the numerator 11 by denominator 28 produces a repeating decimal (approximately 0.392857, or 39.2857%).
Working: 11 ÷ 28 = 0.392857 (39.2857%)

Key Values:
- Simplified Fraction: 11/28
- Mixed Number Form: 11/28
- Decimal Value: 0.392857
- Percentage: 39.2857%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-1-7-plus-2-8/
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1/7 + 2/8 = 11/28

Simplified Fraction

11/28

Mixed Number

Proper (11/28)

Decimal Value

0.392857

Percentage

39.2857%

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Step-by-Step Solution: 1/7 + 2/8

Step 1

Find the Least Common Denominator (LCD)

The denominators 7 and 8 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 7 × 8 = 56.

LCD(7, 8) = 56

Step 2

Convert to Equivalent Fractions with Common Denominator 56

Multiply the numerator and denominator of 1/7 by 8, and multiply the numerator and denominator of 2/8 by 7 so both fractions share the common base 56.

1 × 8/7 × 8 = 8/56 and 2 × 7/8 × 7 = 14/56

Step 3

Add the Numerators

Now add the numerators (8 + 14 = 22) and keep the common denominator 56 unchanged.

8 + 14/56 = 22/56

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 22 and 56, which is 2. Divide both the numerator and denominator by 2.

22 ÷ 2/56 ÷ 2 = 11/28

Step 5

Decimal & Percentage Representation

Dividing the numerator 11 by denominator 28 produces a repeating decimal (approximately 0.392857, or 39.2857%).

11 ÷ 28 = 0.392857 (39.2857%)

Visual Representation

The diagram below illustrates 1/7 plus 2/8 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`11/28`
Mixed Number Form	`11/28`
Decimal Form	`0.392857`
Percentage	`39.2857%`

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Frequently Asked Questions

What is 1/7 plus 2/8 as a fraction?

1/7 + 2/8 in simplest fraction form is 11/28.

What is 1/7 plus 2/8 as a decimal?

1/7 + 2/8 converted to a decimal is 0.392857.

What is 1/7 plus 2/8 as a percentage?

1/7 + 2/8 expressed as a percentage is 39.2857%.

Does 1/7 plus 2/8 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.392857...) because the denominator contains prime factors other than 2 and 5.