The unit has 3 counters on the display. Each counter is numbered (1, 2 or 3). In the picture above, the large "10" count is the #1 counter and is in the "active zone" (the zone which the user is currently counting) and this number can be added to or subtracted from. The other two counts (the "4" and the "2") are in the inactive zones. To move one of these numbers into the active zone, the user simply depresses the small button to the left of the large button in the upper center. This button "rotates" all three counts in a clockwise direction one position at a time. When the numbers are rotated one position, the number "2" comes into the active zone and the user can then add to or subtract from that number.
The user adds to the count in the active zone by depressing the large center button and subtracts by depressing the smaller center button.
The small button in the upper right is the Reset button which resets to 0 any number that is in the active zone when it is depressed. This button also turns off the electronic beep tone if it is held down for 3 seconds.
How is it actually used?
You could start counting ROWS with the number 1 counter. Let's say you have a repeat in your pattern every 10 rows. You start counting your rows with the #1 counter. When you reach 10 in the #1 counter, you ROTATE the numbers one position clockwise until the #3 counter comes into the active zone. This will be used as your REPEAT counter. You then add 1 to this counter meaning you have completed 1 repeat.
You then ROTATE the counters TWICE so that your #1 counter is back in the active zone. Since this will still have a count of 10 in the display, you RESET this number to 0 and then resume counting your rows again until all of your repeats are done.
The whole process goes very quickly once you learn the sequence which is not complex at all (it is actually harder to explain than it is to actually do it).