…that calculation and oral reading exercises are the optimal training methods according the latest brain research?

Have a look at at pictures – they show images of the brain taken by a brain-imaging device during various activities. The red colour on the images indicates an increase in regional cerebral blood flow, while the yellow colour indicates a larger increase in blood flow to areas where brain acitivity is most vigorous.

While you are just watching television, most of the different parts of the brain are barely functioning. These pictures show that solving simple calculations quickly is the most effective way of activating your brain.  (Dr Kawashima, Train Your Brain, 2008)