John,

This was a GOOD problem!

This final version strips the suffix from M30 and adds it, prefixed by a
space, to your answer.

=LEFT(M30,FIND(" ",M30)-1)-LEFT(M31,FIND(" ",M31)-1)&"
"&RIGHT(M30,LEN(M30)-FIND(" ",M30))

I'll go away now.

Pete



"John Sayaff" wrote:

I have measurement data from an ATE system where the results are given as
both a number and 'unit' letters for example 22.3 dB, 2.109 MHz, 12.06 V and
0.175 A. To calculate temperature drift from these readings, I need to
subtract cells that contain both a number and a letter i.e.

2.012 MHz - 2.005 MHz = 0.007
does not matter if the answer contains the 'units' or not.

anyone know how I can achieve this ?