How do I deal with my family which doesn't respect science and math while I am doing a double science and math major?
There is one thing you should actually do: listen to them, even if just a bit.

Your parents are funding your education and are not entirely happy with what you do. They are also proposing to you to get a job during your breaks.
Try to do just that. To elaborate: I think there is a high chance that your parents will not be willing to help you later on (i.e. at M.Sc. level), thus you will need money.

Also, speaking from experience, the sports part is not to be underestimated. You do not have to be a pro-whatever, but going to the gym and keeping fit is certainly not going to hurt your brain.

Beyond this it is up to you to educate them. Look for statistics etc. which
show that having higher education is beneficial for a job and then make it understandable for your parents (basically it should be easy to imagine for them). The latter part is actually the hard part. It seems to me that your parents may have a warped understanding of how difficult it is to actually "get rich quick".

Do not think that trying to educate your parents will be a waste of your time. You might lose some study-time now, but if you are successful you stand to gain much more in the long run (i.e. tuition for masters) – do not underestimate this.