To express 0.40 as a fraction, you start by recognizing that 0.40 is the same as 40 hundredths. This means you can write it as:
0.40 = 40/100
Next, you simplify the fraction. Both the numerator (40) and the denominator (100) can be divided by their greatest common divisor, which is 20:
40 ÷ 20 = 2
100 ÷ 20 = 5
So, when you simplify the fraction, you get:
40/100 = 2/5
In conclusion, 0.40 can be expressed as the fraction 2/5.