1× 1= 1

1×2=2、2×2=4

1×3=3、2×3=6、3×3=9

1×4=4、2×4=8、3×4= 12、4×4= 16

1×5=5、2×5= 10、3×5= 15、4×5=20、5×5=25

1×6=6、2×6= 12、3×6= 18、4×6=24、5×6=30、6×6=36

1×7=7、2×7= 14、3×7=2 1、4×7=28、5×7=35、6×7=42、7×7=49

1×8=8、2×8= 16、3×8=24、4×8=32、5×8=40、6×8=48、7×8=56、8×8=64

1×9=9、2×9= 18、3×9=27、4×9=36、5×9=45、6×9=54、7×9=63、8×9=72、9×9=8 1

Multiplication principle: If the dependent variable F is directly proportional to the independent variables x 1, x2, x3, and each independent variable is qualitatively different, if any independent variable F is missing, it will lose its meaning, which is called multiplication.

In probability theory, the result of an event needs to be divided into n steps, the first step 1 includes M 1 different results, the second step includes M2 different results, …, and the n step includes Mn different results. Then this event may have n = m 1× m2× m3×…× Mn different results.

Multiplication development

In the process of arithmetic development of various civilizations, the generation of multiplication operation is a very important step. A civilization can successfully develop counting methods and addition and subtraction operations, but it is not so easy to create simple and feasible multiplication methods.

The vertical calculation of multiplication we use seems simple, but in fact we need to master the formula table of 99 multiplication in advance; Considering this, this vertical calculation is not perfect. We are about to see what different multiplication methods have been created by different civilizations in the process of mathematical development, and some of them can even completely abandon the multiplication table.