Find closest match - quantity breaks in pricing speadsheet

Please help. I know I will need to do some kind of look up to solve this problem, but don't know how to do it. Please see attached Excel2010 spreadsheet. I need to match quanties in col E with a quantity break quantity columns. Need to find the closest break qty to value in col E. But I don't want the next smallest or next largest value.
I just want the closest value.
So, if break quantities are 20, 40 , 60, 80, 100 a value in col E of 45, must return match for the 40 value
If value in col E is 75, must return match for the 80 value

Columns in Break1, break2, colmns, will always be in asc order.

In the attached spread sheet, the , the cells in break columns highlighted in yellow, match the values in Col E, and the value I want to use is highlighted in orange.

Can this be done? I will appreciate any help I can get on this.