Actually it appears that he did make some of them exact. As I pointed out, " The moon and the sun's most commonly published diameter measurements in miles are 2,160 and 864,000 respectively which equals a ratio of exactly 400.00."
I have never seen an estimate of the Sun's diameter as 864,000 exactly. In any case it's so silly to make this point, because any reasonable person should understand that these are just estimates, and if we did have a way to measure it, all of these numbers would be off, so the ratio would not be exactly 400.00.
If God wanted to prove a point, certainly he would make it to be something which could be easily verifiable. For example, if there was a prediction in the bible which said that on November 10th 2013 all cancer would be cured, and in 5 days from now, this really happened, it would convince me that there is a God.
IF God REALLY wanted everybody to believe in him, what could possibly prevent him from doing this? Certainly it wouldn't take much for the creator of the universe to get rid of cancerous cells.