发现书写规律：后缀teen

（Read in groups，T says：three，S s say：thirteen全部读，个别读）

5.16+1=17 17+1=18 18+1=19（导入 senventeen，eithteen，nineteen） 6.Game：

①（算一算）15+1 13+5 18+1 12+4 9+8 ②数一数狗有多少只腿

T:There are lots of animals in the world，Most animals have legs now，one dog has four legs，two dogs have eight legs Eg：T:two dogs，S:eight legs T:three dogs S：twelve legs

Step3 Dills and practice

1. Show students the PPT".

2. Use "there are to describe the pictures 2.show the crayons：how many crayons are there？let's count（lead in crayon）

show studens the PPT: There are only nineteen crayons，but there are twenty children in the class（此处板书）

Step4 Learn the text

Watch the cartoon with questions:

1.What did Ms Smart buy yesterday？

2.How many crayons did Ms Smart buy yesterday？ How many children are there in the classroom？ Did Ms Smart lose a crayon？ ② Watch again and repeat two times ③Role play next class.

Step5 Consolidation

Let's sing the song： How many do you want？