Biology
posted by Jackie .
If a husband and wife have a 50% chance of having a child with autism (50% of their children should be born with it). In reality, would this 50% ratio be more closely approached if they had FEW children or MANY children?

Statistically, the more children they have, the closer this 50% ratio would be.

but why would this be so...is it because when you have less children the gene may have skipped them so it would be more likelier to show up in the other children?

There's a 50% chance each child will be normal. It's well within the range of probability that the first two children will be normal. But the more children the couple has, then statistically the odds will catch up with them.
Here's an easy way to check this out. You and a friend pretend you're answering a truefalse test. We know there's a 50% chance of getting an answer right. If you each randomly write 50 T  F answers, you should approach 50% agreement. But, on how many answers did you agree for the first two answers? On the first five answers? On the first 10 answers? 
What is 1/1000000 (one divided by a millions) multiplied by 1/1000000 (one divided y a million)?