第1讲自然数(英文版)

2.The teacher thought about an odd number “x” in her heart. Then the two odd numbers adjacent to “x”x+2 are： （ ） and（ ）。 x-2 3.The teacher thought about an evev number “n” in her heart. Then the two odd numbers adjacent to “n” are： （x+2）and（x-2 ）。
Natural numbers
赵金龙
King Leo Math Class
教材分析
学情分析 教材目标 教法学法 教学程序
板书设计
教学反思
一、Essential words
natural number自然数 integer['intidʒə]/whole number整数
odd integer/odd number 奇数
King Leo Math Class
Fill in the circle with proper numbers
103 29 307 520
Odd numbers
44
88 77
Even numbers
6 896 63
King Leo Math Class
1. The sum of three consecutive natural numbers is 23 （ ）、（ 25 24 72. The three numbers are ）、 （ ）。 35 is 2. The sum of three consecutive 31 33 odd numbers 99.The three numbers are（ ）、（ ）、 34 （ ）。 30 32 3.The sum of three consecutive even numbers is 72 ÷3=24 24-1=23 24+1=25 96.The three numbers are（ ）、（ ）、（ ）。
King Leo Math Class
Which of the following numbers are natural numbers?
6 25 3/8 1 47Leabharlann 1/9302551
0.04
302
King Leo Math Class
Fill the parentheses with proper numbers.
even integer/even number偶数
King Leo Math Class
教材分析
学情分析 教材目标 教法学法 教学程序
板书设计
教学反思
Dictataion for essential words ______________自然数 ________________整数
______________奇数
______________偶数
King Leo Math Class
二、Characteristics of natural numbers
1.The number of natural numbers is unlimited. Natural numbers include 0,1,2,3,4,5,6,7........ _______________________________ 2.There's no greatest natural number. 3.The least natural number is 0. Natural numbers are all greater than or equal to 0. _______________________________ 4.The difference of two consecutive natural 连续自然数 numbers is 1.
99÷3=33 33-2=31 33+2=35 96÷3=32 32-2=30 32+2=34
King Leo Math Class
Comprehensive training：
1.The teacher thought about a natural number “a” in her heart. Then the two natural numbers adjacent to a+1 －1：（ “a”aare ）and（ ）.
King Leo Math Class
even numbers
King Leo Math Class All the odd numbers and even numbers between the natural numbers 0 and 30.
Odd numbers:
1、 3 、 5、 7、 9、 11、13、15、17、19、 21、23、25 、 27、29
100
98 99
103 101 102 104
105 106
107
108
King Leo Math Class
Find the characteristics of the following numbers.
1、3、5、7、9、 11、13、15......are singular numbers. 0、2、4、6、8、10、 12、14、16......are double numbers. odd numbers
Even nembers:
2、4、6、8、10 、 12、14、16、18 、 20、 22 、24 、 26 、 28、30
Observe those two groups of numbers,and what can you find out?
Numbers with 1,3,5,7,9 in its ones place are odd numbers. Numbers with 0,2,4,6,8 in its ones place are even numbers.