I have a Honeywell magicstat and would like to know how to set it so the temp in the house will vary about 3 degrees. For instance I would like the heat to be set at 68, I would like the furnace to kick on at 67 and shut off at 70. Hoping to stop the cycling so much. Can I do this, I looked in them manual and did not see it.

You want to change the differential, which as I understand it, is not adjustable on this thermostat. However on the back there are two screws, or switches, which change the number of cycles permitted per hour. Changing this setting may accomplish what you want. One setting allows three cycles per hour. Google your model number for the details.