TO CHINATOWNBOB,,, make a card about 2inches wide with 1 to 30 ft or 1 to 25ft ,,,,, depending what scale you have,, mark half way 30ft scale is 15ft put a line half of 15 to 30ft is 22.5ft, half of 1to 15ft is 7.5ft and so on ad put it under your scale , i fold my to fit under mine,, i have a lab top workes for me ,,, haif of 7.5 is3.75ft half of 22to30 is25.75ft,, half of 15 to 22.5ft isaround 19ftand you get the picture , chinatownbob,, just a thought ,, just a thought,,[hally berry] ,,, i use paper folder or kids cratepaper for my little paper ,,,6to 8inches long ,,, if not e-mail me bob,, rlpparker