Some Plans (especially Sections, Details, and Elevation drawings) use different scales for various regions on the same Plan. The program supports one (and only one) Scale per Page so to accommodate multiple-scales, you must do a little preparation work before you can draw takeoff.
Example
In the screenshot below, the yellow area, at the top, is drawn at 1½” = 1’-0” scale and the lower section, in green, is drawn at ¾” = 1’-0” scale.
To accommodate more than one Scale, you duplicate this Page in the Plan Organizer for each additional Scale represented. Then, update name for each copy to indicate each Scale (you set the scale to match the name of the Page, on the Takeoff Tab).
Open the Plan Organizer and locate the Page that contains multiple Scales.
Select it and the click the 
button.
Notice everything is the same except the "Page No." - it is been appended with "_A" to indicate it is a duplicate.
The program duplicates the Page and places the duplicate copy at the bottom of the list. In our example, we duplicated the last Page in the list so the original and duplicate are next to each other, this is unlikely to be your situation. To make it easier to switch between the two Pages, drag-n-drop the duplicate immediately below the original in the Plan Organizer.
Update the Page Names to show the Scale (if there are more than two Scales, you just repeat this process to accommodate how many unique Scales are included on the Plan).
Click Save and the duplicated Page is added to the Plan Organizer and uploaded
Close the Plan Organizer (if you did not open the P.O. from the Takeoff Tab, return to the Takeoff Tab).
Click the Page Navigator drop-down - notice the original and duplicate in the list.
Set the scale on each Page to match its Page Name.
Verify Scale before drawing any takeoff - see Related Articles for details.
Recap - Steps
In our example we:
- Identified the regions on the Plan that had different scales and determined how many unique Scales were used on that plan
- Opened Plan Organizer and located the Page
- Duplicated that Page (multiple times, if necessary - you'll need one copy for each unique scale represented on that plan)
- Changed the Page Name for each Page to indicate the Scale to which you are going to set the Page
- Saved your changes to the Plan Organizer
- Navigate to each copy of this Page and set its Scale, based upon its Page Name (which includes Scale information from Step 4)
- Verified Scale on each Page, before drawing any takeoff or annotation
Calculating Page Scale