What is 1/18 plus 2/9? (Answer: 5/18)

Exact Answer

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Problem: What is 1/18 plus 2/9?
Formula / Expression: 1/18 + 2/9
Final Answer: 5/18
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
Notice that 18 is an exact multiple of 9 (9 × 2 = 18). The Least Common Denominator (LCD) is simply 18, meaning we only need to scale one fraction.
Working: LCD(18, 9) = 18

Step 2: Convert to Equivalent Fractions with Common Denominator 18
Multiply the numerator and denominator of 1/18 by 1, and multiply the numerator and denominator of 2/9 by 2 so both fractions share the common base 18.
Working: 1 × 1/18 × 1 = 1/18 and 2 × 2/9 × 2 = 4/18

Step 3: Add the Numerators
Now add the numerators (1 + 4 = 5) and keep the common denominator 18 unchanged.
Working: 1 + 4/18 = 5/18

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 5 and 18 is 1, confirming that 5/18 cannot be reduced further—it is already in its simplest irreducible form.
Working: 5/18

Step 5: Decimal & Percentage Representation
Dividing the numerator 5 by denominator 18 produces a repeating decimal (approximately 0.277778, or 27.7778%).
Working: 5 ÷ 18 = 0.277778 (27.7778%)

Key Values:
- Simplified Fraction: 5/18
- Mixed Number Form: 5/18
- Decimal Value: 0.277778
- Percentage: 27.7778%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-1-18-plus-2-9/
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1/18 + 2/9 = 5/18

Simplified Fraction

5/18

Mixed Number

Proper (5/18)

Decimal Value

0.277778

Percentage

27.7778%

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Step-by-Step Solution: 1/18 + 2/9

Step 1

Find the Least Common Denominator (LCD)

Notice that 18 is an exact multiple of 9 (9 × 2 = 18). The Least Common Denominator (LCD) is simply 18, meaning we only need to scale one fraction.

LCD(18, 9) = 18

Step 2

Convert to Equivalent Fractions with Common Denominator 18

Multiply the numerator and denominator of 1/18 by 1, and multiply the numerator and denominator of 2/9 by 2 so both fractions share the common base 18.

1 × 1/18 × 1 = 1/18 and 2 × 2/9 × 2 = 4/18

Step 3

Add the Numerators

Now add the numerators (1 + 4 = 5) and keep the common denominator 18 unchanged.

1 + 4/18 = 5/18

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 5 and 18 is 1, confirming that 5/18 cannot be reduced further—it is already in its simplest irreducible form.

5/18

Step 5

Decimal & Percentage Representation

Dividing the numerator 5 by denominator 18 produces a repeating decimal (approximately 0.277778, or 27.7778%).

5 ÷ 18 = 0.277778 (27.7778%)

Visual Representation

The diagram below illustrates 1/18 plus 2/9 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`5/18`
Mixed Number Form	`5/18`
Decimal Form	`0.277778`
Percentage	`27.7778%`

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Frequently Asked Questions

What is 1/18 plus 2/9 as a fraction?

1/18 + 2/9 in simplest fraction form is 5/18.

What is 1/18 plus 2/9 as a decimal?

1/18 + 2/9 converted to a decimal is 0.277778.

What is 1/18 plus 2/9 as a percentage?

1/18 + 2/9 expressed as a percentage is 27.7778%.

Does 1/18 plus 2/9 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.277778...) because the denominator contains prime factors other than 2 and 5.