I read on one site 1,000 was originally X and M was not introduced until 2 AD.
The lines either side or above are to multiply the original figure by 1000.
I learn so much when I look up people's questions that I am glad they do ask things here!
9Hi to all you squabblers this site is my lifeline I learn so much from other peoples questions and answers. The many generous contributors give us a lift and restore our faith in humanity.
zac,there is also a distinction between some of us who like to get other ABers involved in our Q and A,after all who cares how you find the answer,if you can involve your AB mates,all the better.