64/66 as a percentage is 96.97%. This fraction is very close to one whole, which is why its percentage is just under 100%. It shows that for every 66 parts, 64 of them are present.
When you look at the fraction 64/66, you can think of it as 64 out of 66 equal pieces. In everyday terms, that means almost everything in the set is included, missing only a tiny portion.
Because the percentage is so high, the fraction is often used to illustrate a situation where something is almost complete, like a test score of 96.97% indicating an excellent performance.