when you are taking (4/10) and dividing it by 2. you have a fraction over a fraction. if you remember what you do to the top part of the equation you do to the bottom. so we want to get rid of dividing by 2. (multiple by the reciprocal) the reciprocal of 2 is 1/2. that will cancel out the bottom part of the equation but what you do to the bottom you have to do to the top. so, (4/10) * 1/2 is the same as (4/10) divided by 2. hope that makes sense. it's much easier to write out then type math...
