How to retrun 10 instead of 9 from a Select MAX statement

Hi,
I need to retrieve the largest number in a column.
Using "Select Max(number) as expr1" works OK until I hit 10, which then returns 9 instead.
I understand the select statements returns the series as 1,10,2,3 etc.
How can I phrase the statement to return the correct number.
 
Thanks
 
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