I. Title

1、78x25=、55x36=、87x20=、62x54=、775/5=、2 18/2=、240/8=、 144/9=、56x58=88x94=、 16x2 1=、67x23=、276/6=、96/8=、468/6

2、67x54=，23x54=，63x87=， 176/4=，539/7=，89 1/9=，792/9=24x65=，95x49=， 16x84=84x62=，704/8=，306/6=，539/7=，465/5=，62x85=，63x34

Second, multiplication.

1, multiplication, refers to the shortcut of adding the same numbers. The result of its operation is called product, and "X" is the symbol of multiplication. From the philosophical point of view, multiplication is the result of qualitative change caused by additive quantity. The multiplication of integers (including negative numbers), rational numbers (fractions) and real numbers is a systematic summary of this basic definition.

2. Multiplication can also be regarded as calculating the objects arranged in a rectangle (integer) or finding the area of a rectangle with a given side length. The area of the rectangle does not depend on which side is measured first, which shows the exchange property. The product of two measured values is a new type of measurement, for example, multiplying the length of two sides of a rectangle to get its area, which is the theme of size analysis.

Third, division.

1 and division are one of the four operations. Given the product of two factors and a non-zero factor, the operation of finding another factor is called division. Division of two numbers is also called the ratio of two numbers.

2. If ab=c(b≠0), the operation of finding another factor A by multiplying the product C and the factor B is division, which is marked as c÷b, pronounced as C divided by B, or B divided by C ... where C is called dividend, B is called divisor, and the result of A operation is called quotient.