There are a few ways to establish a FLOOR and CEILING in Excel. One way is to use the =FLOOR(number, significance) and =CEILING(number, significance) functions. For example, if you wanted to round the number 456.789 down to the nearest hundred, you would use the =FLOOR(456.789, 100) function, which would give you the result 400. If you wanted to round the number 456.789 up to the nearest hundred, you would use the =CEILING(456.789, 100) function, which would give you the result 500.

Another way to establish a FLOOR and CEILING in Excel is to use the =ROUNDDOWN(number, num_digits) and =ROUNDUP(number, num_digits) functions. For example, if you wanted to round the number 456.789 down to the nearest hundred, you would use the =ROUNDDOWN(456.789, 2) function, which would give you the result 400. If you wanted to round the number 456.789 up to the nearest hundred, you would use the =ROUNDUP(456.789, 2) function, which would give you the result 500.

You can also use the =MROUND(number, multiple) function to establish a FLOOR and CEILING in Excel. For example, if you wanted to round the number 456.789 down to the nearest hundred, you would use the =MROUND(456.789, 100) function, which would give you the result 400. If you wanted to round the number 456.789 up to the nearest hundred, you would use the =MROUND(456.789,-100) function, which would give you the result 500.