What is 1/8 minus 1/2? (Answer: -3/8)

Exact Answer

==================================================
Problem: What is 1/8 minus 1/2?
Formula / Expression: 1/8 − 1/2
Final Answer: -3/8
==================================================

Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
Notice that 8 is an exact multiple of 2 (2 × 4 = 8). The Least Common Denominator (LCD) is simply 8, meaning we only need to scale one fraction.
Working: LCD(8, 2) = 8

Step 2: Convert to Equivalent Fractions with Common Denominator 8
Multiply the numerator and denominator of 1/8 by 1, and multiply the numerator and denominator of 1/2 by 4 so both fractions share the common base 8.
Working: 1 × 1/8 × 1 = 1/8 and 1 × 4/2 × 4 = 4/8

Step 3: Subtract the Numerators
Now subtract the numerators (1 − 4 = -3) and keep the common denominator 8 unchanged.
Working: 1 − 4/8 = -3/8

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 3 and 8 is 1, confirming that -3/8 cannot be reduced further—it is already in its simplest irreducible form.
Working: -3/8

Step 5: Decimal & Percentage Representation
Dividing the numerator -3 by denominator 8 yields an exact terminating decimal of -0.375 (or -37.5%).
Working: -3 ÷ 8 = -0.375 (-37.5%)

Key Values:
- Simplified Fraction: -3/8
- Mixed Number Form: -3/8
- Decimal Value: -0.375
- Percentage: -37.5%

--------------------------------------------------
Solved with FractionsCalc:
https://fractionscalc.com/what-is-1-8-minus-1-2/
==================================================

1/8 − 1/2 = -3/8

Simplified Fraction

-3/8

Mixed Number

Proper (-3/8)

Decimal Value

-0.375

Percentage

-37.5%

Reduce / Convert Fraction:

Convert Fraction:

Enter Decimal Number:

Enter Percentage: %

What is % of

From Value: To Value:

Simplify Ratio: :

First Number: Second Number:

Find All Factors of:

Dividend: ÷ Divisor:

√ Square Root of: OR Power (x^y): ^{^}

x² + x + = 0

Number (n! & log):

Circle Radius (r):

Side a: Side b:

Angle (Degrees): °

Numbers (comma separated):

Total Items (n): Choose (r):

Decimal Number:

Number (1–3999):

Step-by-Step Solution: 1/8 − 1/2

Step 1

Find the Least Common Denominator (LCD)

Notice that 8 is an exact multiple of 2 (2 × 4 = 8). The Least Common Denominator (LCD) is simply 8, meaning we only need to scale one fraction.

LCD(8, 2) = 8

Step 2

Convert to Equivalent Fractions with Common Denominator 8

Multiply the numerator and denominator of 1/8 by 1, and multiply the numerator and denominator of 1/2 by 4 so both fractions share the common base 8.

1 × 1/8 × 1 = 1/8 and 1 × 4/2 × 4 = 4/8

Step 3

Subtract the Numerators

Now subtract the numerators (1 − 4 = -3) and keep the common denominator 8 unchanged.

1 − 4/8 = -3/8

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 3 and 8 is 1, confirming that -3/8 cannot be reduced further—it is already in its simplest irreducible form.

-3/8

Step 5

Decimal & Percentage Representation

Dividing the numerator -3 by denominator 8 yields an exact terminating decimal of -0.375 (or -37.5%).

-3 ÷ 8 = -0.375 (-37.5%)

Visual Representation

The diagram below illustrates 1/8 minus 1/2 visually:

−

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`-3/8`
Mixed Number Form	`-3/8`
Decimal Form	`-0.375`
Percentage	`-37.5%`

Was this solution helpful?

Help us improve our free step-by-step tools

Frequently Asked Questions

What is 1/8 minus 1/2 as a fraction?

1/8 − 1/2 in simplest fraction form is -3/8.

What is 1/8 minus 1/2 as a decimal?

1/8 − 1/2 converted to a decimal is -0.375.

What is 1/8 minus 1/2 as a percentage?

1/8 − 1/2 expressed as a percentage is -37.5%.

Does 1/8 minus 1/2 result in a terminating or repeating decimal?

It results in an exact terminating decimal (-0.375) because the denominator in simplest terms contains only prime factors 2 and/or 5.