Two cells, adjustment

Hengebru 

It is possible to achieve what you described using formulas in Excel.

In cell A1, you can use a data validation list to allow the user to select a number from 0.5 to 100 with a step of 0.5.

Here are the steps:

1. Select cell A1.
2. Go to the Data tab in the Ribbon.
3. Click on Data Validation.
4. In the Settings tab, choose "List" in the "Allow" box.
5. In the "Source" box, type the following formula: =ROUNDUP(ROW($A$1:$A$199)/2,0.5)
6. Click OK.

This will create a dropdown list in cell A1 with values from 0.5 to 100 in increments of 0.5.

In cell B2, you can use the following formula to calculate the number of panels needed for the distance specified in cell A1:

=CEILING(A1/0.5,1)

This formula divides the value in cell A1 by 0.5 and then rounds up to the nearest whole number using the CEILING function. The second argument of 1 tells Excel to round up to the nearest whole number.

To calculate the distance based on the number of panels, you can use the following formula in another cell:

=B2*0.5

This formula multiplies the number of panels in cell B2 by the width of each panel (0.5) to get the total distance.

I hope this helps!