Step-by-Step Solution for Converting 1.8 to a Fraction

Step 1: Understand the Number

The number 1.8 is a decimal, which can be broken into two parts:

• The whole number part is: 1.
• The decimal part is: 0.8.

We aim to convert the entire number into a fraction.

Step 2: Isolate the Decimal Part (0.8)

Focus on the decimal part (0.8) and represent it as a fraction.

Step 2.1: Write 0.8 as \( \frac80100 \)

The decimal 0.8 can be read as "80 hundredths." Mathematically, this is:

\[ 0.8 = \frac80100 \]

Step 2.2: Simplify the Fraction

Now simplify \( \frac80100 \) by finding the greatest common divisor (GCD) of 80 and 100.

• The GCD of 80 and 100 is: 20.
• Therefore, the simplified fraction is:

\[ \frac45 \]

Step 3: Combine the Whole Number and Fraction

The original number 1.8 is the sum of the whole number 1 and the fraction \( \frac45 \).

Combine these as a mixed number:

\[ 1.8 = 1 + \frac45 = \frac9/5 \]

Step 4: Verify the Answer

To verify, divide \( \frac9/5 \):

\[ \frac9/5 = 1.8 \]

Thus, the fraction is correct.

Final Answer

The decimal 1.8 as a fraction is:

\[ \frac9/5 \]

If expressed as a mixed number:

\[ 1 4/5 \]