Finding numbers missing from a sequence

[andy]

I've just been asked if there's a way Excel can easily find if there are
missing numbers from a sequence of numbers in a column.

For example, the column contains numbers between 1000 and 2000, but the user
isn't sure if every number between 1000 and 2000 is present in the column,
to possibly make it more interesting, each number may appear more than once
in the column.

Any ideas?

Cheers,

Andy

 

[Jonathan Cooper]

use a helper worksheet

starting in cell A1, number from 1000 through 2000.
starting in b1, use a formula =COUNTIF('good data'!$A$1:$A$2000,'helper
sheet'!A1)
copy formula from B1:B1000

now do an autofilter on column B. Filter for value of 0.

 

[Jim Rech]

This is how I'd do it that is pretty easy:

Say you have the numbers 2, 4 and 6 in the range A1:A3. You want to know
which numbers from 1 to 10 are missing.

-Enter the numbers 1 to 10 (use the Fill handle) in C1:C10.
-Enter the formula:

=IF(ISERROR(MATCH(C1,$A$1:$A$3,FALSE)),"x","")

in D1 and copy it down to D10. Now every "x" represents a missing number.

--
Jim
| I've just been asked if there's a way Excel can easily find if there are
| missing numbers from a sequence of numbers in a column.
|
| For example, the column contains numbers between 1000 and 2000, but the
user
| isn't sure if every number between 1000 and 2000 is present in the column,
| to possibly make it more interesting, each number may appear more than
once
| in the column.
|
| Any ideas?
|
| Cheers,
|
| Andy
|
|

 

[andy]

Sorry, only just checked back for replies.

Thanks to both of you for your help.

Andy