What is 9/18 plus 4/5? (Answer: 13/10)

Exact Answer

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Problem: What is 9/18 plus 4/5?
Formula / Expression: 9/18 + 4/5
Final Answer: 1 3/10 (13/10)
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 18 and 5 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 18 × 5 = 90.
Working: LCD(18, 5) = 90

Step 2: Convert to Equivalent Fractions with Common Denominator 90
Multiply the numerator and denominator of 9/18 by 5, and multiply the numerator and denominator of 4/5 by 18 so both fractions share the common base 90.
Working: 9 × 5/18 × 5 = 45/90 and 4 × 18/5 × 18 = 72/90

Step 3: Add the Numerators
Now add the numerators (45 + 72 = 117) and keep the common denominator 90 unchanged.
Working: 45 + 72/90 = 117/90

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 117 and 90, which is 9. Divide both the numerator and denominator by 9.
Working: 117 ÷ 9/90 ÷ 9 = 13/10

Step 5: Convert Improper Fraction to a Mixed Number
Since the numerator (13) is greater than the denominator (10), divide 13 by 10: it goes in 1 whole time(s) with a remainder of 3, giving the mixed number 1 3/10.
Working: 13/10 = 1 3/10

Step 6: Decimal & Percentage Representation
Dividing the numerator 13 by denominator 10 yields an exact terminating decimal of 1.3 (or 130%).
Working: 13 ÷ 10 = 1.3 (130%)

Key Values:
- Simplified Fraction: 13/10
- Mixed Number Form: 1 3/10
- Decimal Value: 1.3
- Percentage: 130%

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Solved with FractionsCalc:
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9/18 + 4/5 = 13/10

Simplified Fraction

13/10

Mixed Number

1 3/10

Decimal Value

1.3

Percentage

130%

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Step-by-Step Solution: 9/18 + 4/5

Step 1

Find the Least Common Denominator (LCD)

The denominators 18 and 5 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 18 × 5 = 90.

LCD(18, 5) = 90

Step 2

Convert to Equivalent Fractions with Common Denominator 90

Multiply the numerator and denominator of 9/18 by 5, and multiply the numerator and denominator of 4/5 by 18 so both fractions share the common base 90.

9 × 5/18 × 5 = 45/90 and 4 × 18/5 × 18 = 72/90

Step 3

Add the Numerators

Now add the numerators (45 + 72 = 117) and keep the common denominator 90 unchanged.

45 + 72/90 = 117/90

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 117 and 90, which is 9. Divide both the numerator and denominator by 9.

117 ÷ 9/90 ÷ 9 = 13/10

Step 5

Convert Improper Fraction to a Mixed Number

Since the numerator (13) is greater than the denominator (10), divide 13 by 10: it goes in 1 whole time(s) with a remainder of 3, giving the mixed number 1 3/10.

13/10 = 13/10

Step 6

Decimal & Percentage Representation

Dividing the numerator 13 by denominator 10 yields an exact terminating decimal of 1.3 (or 130%).

13 ÷ 10 = 1.3 (130%)

Visual Representation

The diagram below illustrates 9/18 plus 4/5 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`13/10`
Mixed Number Form	`1 3/10`
Decimal Form	`1.3`
Percentage	`130%`

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Frequently Asked Questions

What is 9/18 plus 4/5 as a fraction?

9/18 + 4/5 in simplest fraction form is 13/10 (or 1 3/10 as a mixed number).

What is 9/18 plus 4/5 as a decimal?

9/18 + 4/5 converted to a decimal is 1.3.

What is 9/18 plus 4/5 as a percentage?

9/18 + 4/5 expressed as a percentage is 130%.

How do you write 9/18 plus 4/5 as a mixed number?

Because the numerator is greater than the denominator, the improper fraction 13/10 can be written as the mixed number 1 3/10.

Does 9/18 plus 4/5 result in a terminating or repeating decimal?

It results in an exact terminating decimal (1.3) because the denominator in simplest terms contains only prime factors 2 and/or 5.