Answer :

AL2006

Do the decimal first:

Every fraction is a short way to write a division problem.
A fraction means (the top number) divided by (the bottom number).

2/5 means '2' divided by '5' .

When you do that division, you get  0.4 .
That's the decimal equivalent of  2/5 .

Now you need to know how to turn a decimal into a percent.

It's easy.  Just take the decimal, and move the point 2-places to the right.

         0.4  =  40% .