2 × 3 = 6 - 
 Solution : 2 +3 = 5 - 
 3 +1 = 4 - 
 4 × 4 = 16 - 
 3 × 3 +2 = 11 - 
 2 +5 = 7 - 
 21 × 41 = 861 - 
 - 
 4, dozens of dozens of one by one : - 
 - 
 Note: a bit multiply, not use the 0 digit placeholder . - 
 Example : 13 × 326 =? - 
 Example : 11 × 23125 =? - 
 1, ten by ten : - 
 formulas : the head by head ,
gucci sunglass, tail plus tail,
gucci tee shirts, tail by tail. - 
 Example : 21 × 41 =? - 
 1 +2 = 3 - 
 solution : 1 × 1 = 1 - 
 solutions : 2 × 4 = 8 - 
 2 and 5 , respectively, in the end to end - 
 11 × 23125 = 254375 - 
 7 × 4 = 28 - 
 2 +4 = 6 - 
 2. head the same, complementary tail (tail add up to 10 ):-
 5,11 by any number : - 
 solution : 3 +1 = 4 - 
 3, the first multiplier complementary , the same as the other multiplier : - 
 formulas: a first add 1 to the head by head,
conair straightener, tail by tail. - 
 Note: a bit multiply, not use the 0 digit placeholder . - 
 formulas : head by head, head plus head , tail by tail. - 
 Example : 23 × 27 =? - 
 Note : and over ten to get into one. - 
 Solution : 2 +1 = 3 - 
 - 
 Note: a bit multiply, not use the 0 digit placeholder . - 
 solution : 13 bits is 3 - 
 Example : 37 × 44 =? - 
 3 × 2 +6 = 12 - 
 6, a dozen by any number : - 
 2 +4 = 6 - 
 12 × 14 = 168 - 
 1 × 1 = 1 - 
 - 
 - 
 13 × 326 = 4238 - 
 Example : 12 × 14 =? - 
 2 × 4 = 8 - 
 formulas: a first add 1 to the head by head, tail by tail. - 
 37 × 44 = 1628 - 
 23 × 27 = 621 - 
 formulas : sum of fixed fate , and the middle of the drop-down . - 
 3 × 7 = 21 - 
 formulas : the whereabouts of the second movement is not the first multiplier , the first digit multiplied by the factor behind the second factor of each number ,
and now Sin is already in China, plus the next digit , again missing. - 
 3 × 6 = 18 - 
 Note : and over ten to get into one. -