How much magnesium is in Hinode Calrose rice?
This shows that 1 cup of cooked brown rice contains 80mg of magnesium. and white rice contains 50mg.
The wikipedia for brown rice show that for 100g of raw rice it contains 143mg of magnesium, and for white rice it's about 127mg.
The wikipedia page for calrose rice does not display nutritional information.
I would imagine it is similar to regular white rice or it would be stated, especially if it was 3000% of the base value (or about 3810mg) which would be very high.