More than ten by ten: Formulas: First by the head plus tail end, tail by tail. Cases: 12 × 14 =? Solution: 1 × 1 = 1, 2 + 4 = 6, 2 × 4 = 8 → 12 × 14 = 168. Note: Bit multiply, no use of 0-digit placeholder.
2. Head the same, complementary tail (tail sum equals 10): Formulas: First add 1 to the head by head, tail by tail. Cases: 23 × 27 =? Solution: 2 + 1 = 3, 2 × 3 = 6, 3 × 7 = 21 → 23 × 27 = 621. Note: Bit multiply, not enough use the 0-digit placeholder.
3. The first multiplier complementary, the same as another multiplier: Formulas: First add 1 to the head by head, tail by tail. Cases: 37 × 44 =? Solution: 3 + 1 = 4, 4 × 4 = 16, 7 × 4 = 28 → 37 × 44 = 1628. Note: Bit multiply, no use of 0-digit placeholder.
4. Scores of one by dozens of one: Formulas: The first by head, head plus head, tail by tail. Cases: 21 × 41 =? Solution: 2 × 4 = 8, 2 + 4 = 6, 1 × 1 = 1 → 21 × 41 = 861.
5. 11 by any number: Formulas: Sum of fixed fate, and the middle of the drop-down. Cases: 11 × 23125 =? Solution: 2 + 3 = 5, 3 + 1 = 4, 1 + 2 = 3, 2 + 5 = 7, 2 and 5 respectively inclusive → 11 × 23125 = 254375. Note: Sum over 10 carries one.
6. Dozen by any number: Formulas: Second take the first is not the fate of several trends, the first factor of a second factor by multiplying the number behind each, plus the next digit, again whereabouts. Cases: 13 × 326 =? Solution: 13 bits is 3, 3 × 3 + 2 = 11, 3 × 2 + 6 = 12, 3 × 6 = 18 → 13 × 326 = 4238. Note: Sum over 10 carries 1.
**More articles related to topics**: Discount NFL jerseys, true love does not need anything. Today experience a mental illness.