It is known that both sets of numbers contain the same number 123 and 456. Except123123123 *1001,except 4564564538+0. This can simplify the operation, and the specific process is as follows:

456* 123 123 123- 123*456456456

=456*( 123* 100 100 1)- 123*(456* 100 100 1)

=456* 123* 100 100 1- 123*456* 100 100 1

=456* 123* 100 100 1-456* 123* 100 100 1

=456* 123*( 100 100 1- 100 100 1)

=456* 123*0

=0

Extended data:

Significance and counting method of four operations

Addition meaning, subtraction meaning, multiplication meaning, division meaning, addition, subtraction, division, multiplication and check calculation.

Algorithms and simple methods, elementary arithmetic.

Additive commutative law (a+b=b+a), additive associative law (a+(b+c)=(a+b)+c), multiplicative commutative law (a*b=b*a), multiplicative associative law (a*(b*c)=(a*b)*c), and multiplicative distributive law.

Subtraction property: a-(b+c) = a-b-ca-(b-c) = a-b+c.

Classification of operations: addition and subtraction are called first-order operations; Multiplication and division are called two-stage operations (abbreviated)

Composite application problem

Formulas and equations

equation

unit of measure

The speed of progress between length, area and volume, and their similarities.

Quality units and the progress between them

1 ton = 1000 kg = 1000 g.

Time unit exchange rate

1 hour =60 minutes 1 minute =60 seconds

1 = 10.

Ratio and proportion

We can use direct proportion, inverse proportion, simplified proportion, proportion calculation, proportion and fraction, division connection, proportion, proportion and ratio to solve application problems.

Graphics and space

Graph, space, perimeter, area, lateral area, surface area, graph transformation, graph and position, graph understanding and measurement.

Statistics and possibilities

Statistical table, statistical chart, average, median, mode, possibility

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