What can you conclude from these problems ? please discuss with your partners 師:通過這幾組等式的比較,你發(fā)現(xiàn)了什么規(guī)律?請(qǐng)同桌討論?
Boys and girls , please look at the pictures . please discuss with your partner and make up new dialogues 讓學(xué)生根據(jù)圖片進(jìn)行情景對(duì)話,并對(duì)原有的內(nèi)容進(jìn)行擴(kuò)充。
Look at these two equations . can you combine them into one ? please discuss with your partners 師: “請(qǐng)觀察這兩個(gè)關(guān)系式,小組討論一下,能不能把這兩個(gè)關(guān)系式合并成一個(gè)關(guān)系式? ”
Compare problems 2 & 3 with problem 1 . what parts are known in problems 2 & 3 ? and what are we trying to find out ? please discuss with your partners 讓學(xué)生討論后,說出:第( 1 )題是已知兩個(gè)加數(shù),求它們的和,用加法計(jì)算。第( 2 ) 、 ( 3 )題是已知兩個(gè)數(shù)的和與其中的一個(gè)加數(shù),求另一個(gè)加數(shù),用減法計(jì)算。