Four Classic Puzzles per Sheet
At a quarter of the page, a 9x9 puzzle stays readable: islands keep their size and bridges have room to be drawn. Use a sharp pencil, and draw double bridges as two close lines so that they stay easy to count.
One Level, Four Times
Four puzzles at one level, solved back to back, build a habit: Easy sheets the counting reflex, Medium sheets the reflex of checking closed groups, Hard sheets the care to test a bridge before drawing it.
Bigger Networks Next
Once these Hard sheets come easily, the single 11x11 and 13x13 puzzles bring longer bridges and larger networks. The 9x9 Hashi page has the same size at one puzzle per page.