What is 4/30 plus 4/21? (Answer: 34/105)

Exact Answer

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Problem: What is 4/30 plus 4/21?
Formula / Expression: 4/30 + 4/21
Final Answer: 34/105
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 30 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 210 (which is smaller than their product 30 × 21 = 630, keeping the calculation simpler).
Working: LCD(30, 21) = 210

Step 2: Convert to Equivalent Fractions with Common Denominator 210
Multiply the numerator and denominator of 4/30 by 7, and multiply the numerator and denominator of 4/21 by 10 so both fractions share the common base 210.
Working: 4 × 7/30 × 7 = 28/210 and 4 × 10/21 × 10 = 40/210

Step 3: Add the Numerators
Now add the numerators (28 + 40 = 68) and keep the common denominator 210 unchanged.
Working: 28 + 40/210 = 68/210

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 68 and 210, which is 2. Divide both the numerator and denominator by 2.
Working: 68 ÷ 2/210 ÷ 2 = 34/105

Step 5: Decimal & Percentage Representation
Dividing the numerator 34 by denominator 105 produces a repeating decimal (approximately 0.32381, or 32.381%).
Working: 34 ÷ 105 = 0.32381 (32.381%)

Key Values:
- Simplified Fraction: 34/105
- Mixed Number Form: 34/105
- Decimal Value: 0.32381
- Percentage: 32.381%

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Solved with FractionsCalc:
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4/30 + 4/21 = 34/105

Simplified Fraction

34/105

Mixed Number

Proper (34/105)

Decimal Value

0.32381

Percentage

32.381%

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Step-by-Step Solution: 4/30 + 4/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 30 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 210 (which is smaller than their product 30 × 21 = 630, keeping the calculation simpler).

LCD(30, 21) = 210

Step 2

Convert to Equivalent Fractions with Common Denominator 210

Multiply the numerator and denominator of 4/30 by 7, and multiply the numerator and denominator of 4/21 by 10 so both fractions share the common base 210.

4 × 7/30 × 7 = 28/210 and 4 × 10/21 × 10 = 40/210

Step 3

Add the Numerators

Now add the numerators (28 + 40 = 68) and keep the common denominator 210 unchanged.

28 + 40/210 = 68/210

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 68 and 210, which is 2. Divide both the numerator and denominator by 2.

68 ÷ 2/210 ÷ 2 = 34/105

Step 5

Decimal & Percentage Representation

Dividing the numerator 34 by denominator 105 produces a repeating decimal (approximately 0.32381, or 32.381%).

34 ÷ 105 = 0.32381 (32.381%)

Visual Representation

The diagram below illustrates 4/30 plus 4/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`34/105`
Mixed Number Form	`34/105`
Decimal Form	`0.32381`
Percentage	`32.381%`

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Frequently Asked Questions

What is 4/30 plus 4/21 as a fraction?

4/30 + 4/21 in simplest fraction form is 34/105.

What is 4/30 plus 4/21 as a decimal?

4/30 + 4/21 converted to a decimal is 0.32381.

What is 4/30 plus 4/21 as a percentage?

4/30 + 4/21 expressed as a percentage is 32.381%.

Does 4/30 plus 4/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.32381...) because the denominator contains prime factors other than 2 and 5.