i'm trying to pull a sum of each column from all 13 sheets onto a summary sheet using a combination of sum and vlookup.
f(x): =SUM(VLOOKUP($A3,'Jan 16'!$A:B,2,0))+(VLOOKUP($A3,'Feb 16'!$A:B,2,0))+(VLOOKUP($A3,'Mar 16'!$A:B,2,0))+(VLOOKUP($A3,'Apr 16'!$A:B,2,0))+(VLOOKUP($A3,'May...