|The only way to enter a number in a cell and have Excel automatically perform an operation on that same cell is with a Worksheet_Change macro written in VBA.|
Now that we know that, we need a little more information before we could offer any code.
re: "For example, if Cells A1 to A10..."
Since the code needs to act a specific range of cells, such as a column or a row or a specific range such as A1:A10, you'll need to be more specific than "For example...". Where exactly are you entering these numbers?
re: "i need to round to the nearest 5"
Give us some examples of your prices and what they should round to. "To the nearest 5" could mean a number of things:
e.g. Does rounding $123.57 "to the nearest 5" mean $123.55 or $125 or something else?
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