In my native language (not Japanese), the Sino-Xenic word for "ten thousand" (萬) is only used in historical contexts. In modern times, the Western way of counting in thousands is much preferred, and thousand separators are used. All that makes it quite difficult to intuitively discern large numbers in Japanese, because Japanese counts in myriads instead. After ten thousand (一万), it starts to become more difficult to immediately know what larger numbers, like say 二百五十万, actually mean, without taking some time to break them down.
So is there a methodology for practicing thinking in myriads in order to count more easily in Japanese?