Change fmt of a cell if number matches any in a range of cells?

[SteveR]

I want to change the format of a cell when a number in that cell matches any
number in a largerrange of cells (50 Cells).

 

[Gary''s Student]

Use conditional Formatting:

Select B1
Pull-down:

Format > Condition Formatting
Select formula is and for the formula
=COUNTIF(A$1:A$50,B1)>0

 

[Ardus Petus]

Conditional formatting with formula:
=NOT(ISNA(MATCH(A1,$B$1:$B$100)

HTH