To convert the decimal 0.4 into a fraction, we can follow a simple process. First, we note that 0.4 can be read as ‘four tenths’ since the digit 4 is in the tenths place. This means we can express it as:
0.4 = 4/10
Next, we can simplify this fraction by finding the greatest common divisor (GCD) of the numerator (4) and the denominator (10). The GCD of 4 and 10 is 2. Therefore, we can divide both the numerator and the denominator by 2:
4 ÷ 2 = 2
10 ÷ 2 = 5
So, when we simplify 4/10, we get:
2/5
Therefore, 0.4 as a fraction in its simplest form is 2/5.