1 one 11 eleven 20twenty 2 two 12 twelve 30thirty 3 three 13 thirteen 4 four 14 fourteen 5 five 15 fifteen 6 six 16 sixteen 7 seven 17 seventeen 8 eight 18 eighteen 9 nine 19 nineteen 10 ten,How many books do I have,Lesson 5,40forty(圈上) 50 fifty 60 sixty 70 seventy 80 eighty（圈上） 90 ninety 100 one hundred,Lets learn more numbers! 让我们学习更多的数字,Lets+动词原形 例如： Lets learn Lets play Lets sing,thirty,forty,fifty,thirteen,fourteen,fifteen,sixteen,seventeen,eighteen,nineteen,twenty+ twenty fifty twenty-five
