Johnson Level & Tool Mfg. 40-6001 - Manual (Page 14)

14 ©2013 Johnson Level & Tool - Rev. 3
To add another measurement to sum (repeat same measurement
sequence) to tally.
To subtract a value in the tally sequence press button.
This laser distance measure has the capability to add or subtract area,
volume or indirect measurement calculations. For example, if you need
the square footage of four rooms this instrument will allow you to add
each area calculation together to sum the dimensions of the four rooms.
The same holds true for volume or indirect measurement modes.
Please see each respective measurement section for the step-by-step
instructions.