I'm not sure what you mean by "The data goes into separate cells". One word
per cell, one number per cell, one sentence per cell?
You may have text numbers in your cells, not numerics. They appear as left
justified numbers. You can convert the text numbers to numeric. An easy way
is to copy a 0 (zero) from a cell and paste special, operation, add. That
will add 0 to the text numbers and change them to numeric.

Tyro

To add to Tyro's post,

When you copy from the web you often
get  a lot of non-breaking spaces (google for an explanation)

To get rid of them go to Edit>Replace
Replace what:  Alt+0160
Replace with:   Leave this box blank
Click Replace all

To type unicode
Hold down the Alt Key
Type 0160 (on the number pad only)
Let go of the Alt key

HTH
Martin

One thing to try in addition to the other suggestions.

Could be numbers are really text so calculations won't take place.

Format all to General then copy an empty cell.

Select the data and Edit>Paste Special(in place)>Add>OK>Esc

Gord Dibben  MS Excel MVP