Originally Posted by
coopah
I only know this because I had to teach it to second graders. :-)
When I was living in Japan I always carried a tape measure with English measurements on one side and metric measurements on the other. Just take a measurement with one system, flip the tape measure over and you have the other measurement on the reverse. This came in handy for me when shopping for curtains and clothes. I still carry the double-sided tape measure with me today.