I vote for math. You will have several years to teach reading. But the ability to learn Doman math is decreasing with every day. And the interest on such learning is decreasing. I think you should start today

. According to my experience, it will be hard to keep the interest after 12 months, and almost useless after 18 months.
Math software. You do not need it with 6 months old child because they are happy to watch black dots. Older children need more entertainment which is provided by LM. But you can try paper or powerpoint at first.
Of course, you can do math and reading, and EK together. Most of mothers do. Until 12 months, my kid was very interested in art; now he has no interest on it.
I just wanted to say that it can be a mistake, to teach math AFTER reading.