Need way to self populate multiple cells based on selection from drop down with NUMBERS

This is what I need and what I already know: (Using Excel 2010)

1. Have drop down with fraction sizes
2. Depending on which fraction size is chosen, multiple cells will be populated with a corresponding decimal weight.
3. Need multiple cells to populate a set of data based on a single drop down menu.

For Example

If I select 3/8 from a drop down list in A1, then B1 automatically populates with a specific weight that is tied to 3/8
If I then select 1/2 from the same drop down in A1, then B1 would populate with a different weight that is tied to 1/2

I've been here: http://www.contextures.com/xldataval02.html

It helped me almost get there, but I want the B2 cell to SELF POPULATE with a single specific weight after I have made a selection in the drop down from A1. Also, these tips become more difficult when working with fractions and numbers and not words. I'm willing to hear any suggestions including formulas and vba codes. Also, If giving a formula, please explain each piece so I can potentially make changes or additions to the formula while still knowing what each piece means. THANK YOU.