= 1000× 100- 1000- 100+ 1

=99000- 100+ 1

=98900+ 1

=9890 1

Extended data:

1, a simple calculation rule of multiplication:

Multiplicative commutative law: a*b=b*a, multiplicative associative law: a*b*c=(a*b)*c=a*(b*c), multiplicative distributive law: (a+b) * c = a * c+b * c; (a-b)*c=a*c-b*c .

2. Simple calculation rule of addition: additive commutative law; Additive associative law.

3. Simple calculation rule of subtraction: basic properties of subtraction.

4. Simple calculation rule of division: the basic nature of division; Invariance of quotient.