For something a little more involved, this is what I taught a guy recently with dyslexia.
think of purchase price as $100, and deal in %s of that.
in costs 4% (may be 5% for some states)
add 1.5% if LMI
add 2.5% if Buyer's Agent
interest = whatever x lvr, say:
100% lend = 8%
75% lend, 8*3/4...