4.2 as a Fraction

Learn how to convert the decimal number 4.2 to a fraction. We'll show you the answer and walk through the conversion process step by step.

Answer:

4.2 = 4 ¹/₅ or ²¹/₅

4.2 as a fraction is 21/5 or 4 1/5 (mixed number)

Follow these steps to convert 4.2 to a fraction:

Step 1

Start by writing 4.2 as a fraction with 1 as the denominator:

4.2 = 4.2/1

Step 2

Since there are 1 digit(s) after the decimal point, multiply both numerator and denominator by 10:

(4.2 × 10) / (1 × 10) = 42/10

Step 3

Find the Greatest Common Divisor (GCD) of 42 and 10, which is 2. Divide both numerator and denominator by 2:

(42 ÷ 2) / (10 ÷ 2) = 21/5

Step 4

Since 21/5 is an improper fraction (numerator is larger than denominator), we can convert it to a mixed number:

21 ÷ 5 = 4 remainder 1, so 21/5 = 4 1/5

Final Answer: 4.2 = 4 1/5 (mixed number) or 21/5 (improper fraction)