The trick was to take off the decimal place on the calculator that my failing eyesight could not see at first. But on those sums I work backwards up the list
Try this one...for fun...it only has 48 pieces... http://www.jigzone.com/puzzles/C9122233786 Average time....10mins - 28secs Fastest time.....4mins - 32secs
Try this one... http://www.jigzone.com/puzzles/D412DE366B5 Times... Fastest 6.18 average 15.21 mine 14.11