【文档说明】清华版英语三年级上册《unit 3 let's do math lesson 17》PPT课件(共15页).ppt，共(15)页，2.521 MB，由小喜鸽上传

转载请保留链接：https://www.ichengzhen.cn/view-162922.html

以下为本文档部分文字说明：

UNIT3LET’SDOMATHLESSON1720~90的十位数的整数均以后缀-ty结尾20twenty30thirty40forty50fifty60sixty70seventy80eighty90

ninetyAgain2030405060twentythirtyfortyfiftysixty708090100seventyeightyninetyonehundredLet’sdoitTherearefortybananas.Mybrothertookawayten.Howmanyba

nanasareleft?40-10=30Fortyminustenisthirty.Thirtybananasareleft.Therearefiftyapples.Mysistertookawaytwenty.Howmanyapplesare

left?50-20=30Fiftyminustwentyisthirty.Thirtyapplesareleft.Therearefiftyeggs.Mymothertookawaythirty.Howmanyeggsar

eleft?50-30=20Fiftyminusthirtyistwenty.Twentyeggsareleft.Therearesixtypears.Myfathertookawayten.Howma

nypearsareleft?60-10=50Sixtyminustenisfifty.Fiftypearsareleft.Practice1.90-20=?2.80-20=?Ninetyminustwentyis________

.Eightyminustwentyis________.Onehundredminustwentyis________.3.100-20=?seventysixtyeightyFiftyminusthirtyis________.Sixtyminusthirtyis

________.Ninetyminusfortyis________.4.50-30=?5.60-30=?6.90-40=?twentythirtyfiftyHomework:回家把今天学到的数字数给爸爸妈妈听。