Sometimes users need to convert the Non-number values (like, YES/NO, date/time) into Numeric value. To convert non-number values, you don’t need to manually enter the corresponding value, Excel 2010 offers a simple formula which can evaluate any supported Non-number and show its respective number value.
To convert non-number into number, N function comes in handy. To use it, head over to Formulas tab, and from More Functions, under Information category, select N.
Function Arguments dialog will appear, enter the argument. you can enter non-number values, date & time serials, etc to change into number value. You can also enter location of cells rather than direct values as arguments.