What is 1/8 plus 7/9? (Answer: 65/72)

Exact Answer

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Problem: What is 1/8 plus 7/9?
Formula / Expression: 1/8 + 7/9
Final Answer: 65/72
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 8 and 9 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 8 × 9 = 72.
Working: LCD(8, 9) = 72

Step 2: Convert to Equivalent Fractions with Common Denominator 72
Multiply the numerator and denominator of 1/8 by 9, and multiply the numerator and denominator of 7/9 by 8 so both fractions share the common base 72.
Working: 1 × 9/8 × 9 = 9/72 and 7 × 8/9 × 8 = 56/72

Step 3: Add the Numerators
Now add the numerators (9 + 56 = 65) and keep the common denominator 72 unchanged.
Working: 9 + 56/72 = 65/72

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 65 and 72 is 1, confirming that 65/72 cannot be reduced further—it is already in its simplest irreducible form.
Working: 65/72

Step 5: Decimal & Percentage Representation
Dividing the numerator 65 by denominator 72 produces a repeating decimal (approximately 0.902778, or 90.2778%).
Working: 65 ÷ 72 = 0.902778 (90.2778%)

Key Values:
- Simplified Fraction: 65/72
- Mixed Number Form: 65/72
- Decimal Value: 0.902778
- Percentage: 90.2778%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-1-8-plus-7-9/
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1/8 + 7/9 = 65/72

Simplified Fraction

65/72

Mixed Number

Proper (65/72)

Decimal Value

0.902778

Percentage

90.2778%

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Step-by-Step Solution: 1/8 + 7/9

Step 1

Find the Least Common Denominator (LCD)

The denominators 8 and 9 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 8 × 9 = 72.

LCD(8, 9) = 72

Step 2

Convert to Equivalent Fractions with Common Denominator 72

Multiply the numerator and denominator of 1/8 by 9, and multiply the numerator and denominator of 7/9 by 8 so both fractions share the common base 72.

1 × 9/8 × 9 = 9/72 and 7 × 8/9 × 8 = 56/72

Step 3

Add the Numerators

Now add the numerators (9 + 56 = 65) and keep the common denominator 72 unchanged.

9 + 56/72 = 65/72

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 65 and 72 is 1, confirming that 65/72 cannot be reduced further—it is already in its simplest irreducible form.

65/72

Step 5

Decimal & Percentage Representation

Dividing the numerator 65 by denominator 72 produces a repeating decimal (approximately 0.902778, or 90.2778%).

65 ÷ 72 = 0.902778 (90.2778%)

Visual Representation

The diagram below illustrates 1/8 plus 7/9 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`65/72`
Mixed Number Form	`65/72`
Decimal Form	`0.902778`
Percentage	`90.2778%`

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Frequently Asked Questions

What is 1/8 plus 7/9 as a fraction?

1/8 + 7/9 in simplest fraction form is 65/72.

What is 1/8 plus 7/9 as a decimal?

1/8 + 7/9 converted to a decimal is 0.902778.

What is 1/8 plus 7/9 as a percentage?

1/8 + 7/9 expressed as a percentage is 90.2778%.

Does 1/8 plus 7/9 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.902778...) because the denominator contains prime factors other than 2 and 5.