What is 5/54 plus 7/21? (Answer: 23/54)

Exact Answer

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Problem: What is 5/54 plus 7/21?
Formula / Expression: 5/54 + 7/21
Final Answer: 23/54
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 54 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 378 (which is smaller than their product 54 × 21 = 1134, keeping the calculation simpler).
Working: LCD(54, 21) = 378

Step 2: Convert to Equivalent Fractions with Common Denominator 378
Multiply the numerator and denominator of 5/54 by 7, and multiply the numerator and denominator of 7/21 by 18 so both fractions share the common base 378.
Working: 5 × 7/54 × 7 = 35/378 and 7 × 18/21 × 18 = 126/378

Step 3: Add the Numerators
Now add the numerators (35 + 126 = 161) and keep the common denominator 378 unchanged.
Working: 35 + 126/378 = 161/378

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 161 and 378, which is 7. Divide both the numerator and denominator by 7.
Working: 161 ÷ 7/378 ÷ 7 = 23/54

Step 5: Decimal & Percentage Representation
Dividing the numerator 23 by denominator 54 produces a repeating decimal (approximately 0.425926, or 42.5926%).
Working: 23 ÷ 54 = 0.425926 (42.5926%)

Key Values:
- Simplified Fraction: 23/54
- Mixed Number Form: 23/54
- Decimal Value: 0.425926
- Percentage: 42.5926%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-5-54-plus-7-21/
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5/54 + 7/21 = 23/54

Simplified Fraction

23/54

Mixed Number

Proper (23/54)

Decimal Value

0.425926

Percentage

42.5926%

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Step-by-Step Solution: 5/54 + 7/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 54 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 378 (which is smaller than their product 54 × 21 = 1134, keeping the calculation simpler).

LCD(54, 21) = 378

Step 2

Convert to Equivalent Fractions with Common Denominator 378

Multiply the numerator and denominator of 5/54 by 7, and multiply the numerator and denominator of 7/21 by 18 so both fractions share the common base 378.

5 × 7/54 × 7 = 35/378 and 7 × 18/21 × 18 = 126/378

Step 3

Add the Numerators

Now add the numerators (35 + 126 = 161) and keep the common denominator 378 unchanged.

35 + 126/378 = 161/378

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 161 and 378, which is 7. Divide both the numerator and denominator by 7.

161 ÷ 7/378 ÷ 7 = 23/54

Step 5

Decimal & Percentage Representation

Dividing the numerator 23 by denominator 54 produces a repeating decimal (approximately 0.425926, or 42.5926%).

23 ÷ 54 = 0.425926 (42.5926%)

Visual Representation

The diagram below illustrates 5/54 plus 7/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`23/54`
Mixed Number Form	`23/54`
Decimal Form	`0.425926`
Percentage	`42.5926%`

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Frequently Asked Questions

What is 5/54 plus 7/21 as a fraction?

5/54 + 7/21 in simplest fraction form is 23/54.

What is 5/54 plus 7/21 as a decimal?

5/54 + 7/21 converted to a decimal is 0.425926.

What is 5/54 plus 7/21 as a percentage?

5/54 + 7/21 expressed as a percentage is 42.5926%.

Does 5/54 plus 7/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.425926...) because the denominator contains prime factors other than 2 and 5.