it's a wonderfoo world's thoughtFooness sharing ...

For those having problem multiply 2 digit x 2 digit mentally, this method may be faster for you:   １４×１３：    （１）１４+３＝１７    （２）１７×１０＝１７０    （３）４×３＝１２     （４）１７０+１２＝１８２               １６×１７：    （１）１６+７＝２３     （２）２３×１０＝２３０     （３）６×７＝４２     （４）２３０+４２＝２７２          １９×１９        （１）１９+９＝２８        （２）２８×１０＝２８０        （３）９×９＝８１        （４）２８０+８１＝３６１