Speed ​​calculation, reserve education kid the fu

1. ten by ten:
formulas: the head by head, tail plus tail, tail by tail.
Example: 12 × 14 =?
solution: 1 × 1 = 1
2 +4 = 6
2 × 4 = 8
12 × 14 = 168
Note: a bit multiply, not use the 0 digit placeholder.

2. head the same, complementary tail (tail increase up to 10):
formulas: a first add 1 to the head by head, tail by tail.
Example: 23 × 27 =?
Solution: 2 +1 = 3
2 × 3 = 6
3 × 7 = 21
23 × 27 = 621
Note: a morsel multiply,Lacoste Swerve Lace Trainers, not use the 0 digit placeholder.

3. complementary first multiplier, the same for the additional multiplier:
formulas: a first add 1 to the head by head, tail by tail.
Example: 37 × 44 =?
solution: 3 +1 = 4
4 × 4 = 16
7 × 4 = 28
; 37 × 44 = 1628
Note: a bit multiply,Lacoste R75 P2 Trainers, not use the 0 digit placeholder.

4. dozens of dozens of one by one:
formulas: head by head, brain plus head,Lacoste Finham SPM Trainers, tail by tail.
Example: 21 × 41 =?
solutions: 2 × 4 = 8
2 +4 = 6
1 × 1 = 1
; 21 × 41 = 861

5.11 by any number:
formulas: sum of nailed fate,Womens Lacoste Trainers, and the navel of the drop-down.
Example: 11 × 23125 =?
Solution: 2 +3 = 5
3 +1 = 4
1 +2 = 3
; 2 +5 = 7
2 and 5,Womens Lacoste Carnaby Trainers, respectively, in the sum of
11 × 23125 = 254375
Note: and over ten to get into 1.

6. dozen by any number:
formulas: Second Take namely not the 1st destiny of several trends,Lacoste Carnaby Trainers, the premier numeral multiplied along the factor backward the second element of each digit, and the afterward numeral, another missing.
Example: 13 × 326 =?
solution: 13 bits is 3
3 × 3 +2 = 11
3 × 2 +6 = 12
; 3 × 6 = 18
13 × 326 = 4238
Note: and over ten to get into one.