How do I convert 0.4 into a fraction explain

I have got a really good answer:

.4 is in the tenths place, so you write it like you say it:

4 over 10 (4/10)

then you reduce it to 2/5

The decimal number 0.4 is equivalent to 4/10 in fraction form. This fraction can be reduced to its simplest form by dividing both the numerator and the denominator by their greatest common factor. The GCF of four and 10 is two. Therefore, 0.4 is equal to 2/5.