If the data structure is consistent down the col, think it's good to split
the numbers from the text via Data > Text to columns
Assume data below is in col A, A1 down
20 Text1
21 Text1
22 Text1
23 Text1
24 Text1
25 Text1
To split, select col A
Click Data > Text to columns
(Delimited will be selected)
Click Next, and check "Space" in step2
Click Finish
Col A will be split into cols A and B
(Ensure you have sufficient empty cols to the right to receive the split
portions before proceeding)
Alternatively, you could also "split" the number / text in col A
into 2 adjacent cols using formulas ..
Put in B1: =LEFT(A1,SEARCH(" ",TRIM(A1))-1)+0
Put in C1: =MID(A1,SEARCH(" ",TRIM(A1))+1,99)
(the "99" in MID is just an arbitrary figure, adjust to suit)
Select B1:C1 and copy down
Then just point formulas to col B for your calcs on the numbers