Step 1: Identify the number of decimal places

The decimal 1.263851 has 6 decimal places.

Step 2: Multiply by the appropriate power of 10

Multiply by 10⁶ = 1000000 to eliminate the decimal point.

1.263851 × 1000000 = 1263851

Step 3: Write as a fraction

Step 4: Simplify the fraction

Find the greatest common divisor (GCD) of 1263851 and 1000000.

GCD(1263851, 1000000) = 1

Divide both the numerator and denominator by the GCD: