What is 7/9 plus 7/8? (Answer: 119/72)

Exact Answer

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Problem: What is 7/9 plus 7/8?
Formula / Expression: 7/9 + 7/8
Final Answer: 1 47/72 (119/72)
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Step-by-Step Solution:

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

Step 2: Convert to Equivalent Fractions with Common Denominator 72
Multiply the numerator and denominator of 7/9 by 8, and multiply the numerator and denominator of 7/8 by 9 so both fractions share the common base 72.
Working: 7 × 8/9 × 8 = 56/72 and 7 × 9/8 × 9 = 63/72

Step 3: Add the Numerators
Now add the numerators (56 + 63 = 119) and keep the common denominator 72 unchanged.
Working: 56 + 63/72 = 119/72

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 119 and 72 is 1, confirming that 119/72 cannot be reduced further—it is already in its simplest irreducible form.
Working: 119/72

Step 5: Convert Improper Fraction to a Mixed Number
Since the numerator (119) is greater than the denominator (72), divide 119 by 72: it goes in 1 whole time(s) with a remainder of 47, giving the mixed number 1 47/72.
Working: 119/72 = 1 47/72

Step 6: Decimal & Percentage Representation
Dividing the numerator 119 by denominator 72 produces a repeating decimal (approximately 1.652778, or 165.2778%).
Working: 119 ÷ 72 = 1.652778 (165.2778%)

Key Values:
- Simplified Fraction: 119/72
- Mixed Number Form: 1 47/72
- Decimal Value: 1.652778
- Percentage: 165.2778%

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Solved with FractionsCalc:
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7/9 + 7/8 = 119/72

Simplified Fraction

119/72

Mixed Number

1 47/72

Decimal Value

1.652778

Percentage

165.2778%

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

Step 1

Find the Least Common Denominator (LCD)

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

LCD(9, 8) = 72

Step 2

Convert to Equivalent Fractions with Common Denominator 72

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

7 × 8/9 × 8 = 56/72 and 7 × 9/8 × 9 = 63/72

Step 3

Add the Numerators

Now add the numerators (56 + 63 = 119) and keep the common denominator 72 unchanged.

56 + 63/72 = 119/72

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 119 and 72 is 1, confirming that 119/72 cannot be reduced further—it is already in its simplest irreducible form.

119/72

Step 5

Convert Improper Fraction to a Mixed Number

Since the numerator (119) is greater than the denominator (72), divide 119 by 72: it goes in 1 whole time(s) with a remainder of 47, giving the mixed number 1 47/72.

119/72 = 147/72

Step 6

Decimal & Percentage Representation

Dividing the numerator 119 by denominator 72 produces a repeating decimal (approximately 1.652778, or 165.2778%).

119 ÷ 72 = 1.652778 (165.2778%)

Visual Representation

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

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`119/72`
Mixed Number Form	`1 47/72`
Decimal Form	`1.652778`
Percentage	`165.2778%`

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Frequently Asked Questions

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

7/9 + 7/8 in simplest fraction form is 119/72 (or 1 47/72 as a mixed number).

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

7/9 + 7/8 converted to a decimal is 1.652778.

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

7/9 + 7/8 expressed as a percentage is 165.2778%.

How do you write 7/9 plus 7/8 as a mixed number?

Because the numerator is greater than the denominator, the improper fraction 119/72 can be written as the mixed number 1 47/72.

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

It results in a repeating decimal (approximately 1.652778...) because the denominator contains prime factors other than 2 and 5.