For example, 12 and ten digits are all 3, and 3 is a multiple of 3, so 12 is also a multiple of 3. 105 bits add up to 6, and 6 is a multiple of 3, so 105 is also a multiple of 3. A multiple is defined as an integer divisible by another integer, so this integer is a multiple of another integer.
First, the position, function and context of teaching materials:
The characteristic of the multiple of 3 is the content of the fifth volume of Primary Mathematics published by People's Education Publishing House, which belongs to the field of "number and algebra" and is based on knowledge.
Systematic teaching based on factors and multiples to seek the greatest common divisor.
The least common multiple is an important foundation and a necessary prerequisite for learning divisor and general fraction. Therefore, it is of great significance for students to master the characteristics of numbers 2, 5 and 3. The writing intention of the textbook highlights students' independent exploration.
Make students sum up the characteristics of multiples of 3 in the process of observation-conjecture-disproving conjecture-observation-conjecture-verification. In the teaching material, the method of gradually increasing hints is adopted to slow down the thinking difficulty of students' generalization.
Second, the analysis of learning situation:
Students learn the characteristics of multiples of 2 and 5, and then learn the characteristics of multiples of 3. Because the characteristics of multiples of 2 and 5 only reflect?
The figures in the unit are obvious and easy to understand. The characteristics of multiples of surface 3 can't be judged only by the number in the unit, must it be?
It is necessary to add up the numbers on each bit to see if the total is a multiple of 3. ?