Let's write 0.8 as a fraction. So 0.8, the 8 right over here is in the tenths place. It is in the tenths place. So you can read this as 8 tenths (or 8/10). And we can write that, literally, as being equal to 8 tenths, or 8 over 10 (or 8/10). And now, we've already written it as a fraction. And if we want, we can simplify this down. Both 8 and 10 share common factors. They are both divisible by 2. So let's divide both the numerator and the denominator by 2. We're not changing the value of the fraction, because we are dividing both the numerator and the denominator by the same thing. 8 ÷ 2 is 4. 10 ÷ 2 is 5. And we're done. 0.8 is the same thing as 8 tenths (or 8/10), which is the same thing as 4 fifths (or 4/5).