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Teaching plan give typical examples

 Education requirement:
  masters the definition that forms number, show a sign, master the derivation that arranges several formula to reach apply.
 Key difficulty:
  forms number formula and arrange those who count formula to be out of shape
 Education content:
  one, review a query:
  1. Multiplication principle: NM1×M2× ... ×MN
  2. Arrange a definition
  3. Exercise:
  ① by 2, 3, 4, 5, the 6 3 digit that how many can you comprise to did not repeat a figure? (4 × of 5 × 3 = 60 ()
In the element that   ② differs from 11, how many does the permutation that allows to take 10 elements share?
  (10 × of 11 × 8 × of 9 × 6 × of 7 × 4 × of 5 × 2 = of 3 × 39 916 800 ()
  is becomeN, Mwhen the number is larger, a number that calculate all permutation so is more troublesome.
  2, award newly:
  1. Arrange several definitions
  fromNTake out in different elementM(MN) a number that all permutation of the element, be called fromNTake out in different elementM