=( 100+3)x63

= 100x63+3x63

=6300+ 189

=6489

Principle: It is very convenient to calculate with books such as integer ten and integer hundred. Taking the complex 103 as 100+3 can simplify the calculation steps.

：

1, one of the simple operations of multiplication-skillfully using multiplication commutative law and multiplication associative law to perform simple operations.

2. The second simple operation of multiplication-skillfully using the distribution law of multiplication.

There are two forms of application of multiplication distribution law: forward multiplication distribution law and backward multiplication distribution law. The specific usage is as follows:

3. The second simple operation of multiplication-the complex usage of the law of multiplication and distribution.

Some simple operation problems that seem to be unable to apply the multiplication table directly need to be deformed before they can be solved with the multiplication table.