三步计算式题1.ppt

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,三步计算式题,四年级第一学期,2,3,6,9,2,6,=12,3,+12=15,15+,9,=24,9,+,6,=15,15,3,=12,12,2,=24,2,+,3,=5,9,5=4,4,6,=24,2,+,6,=8,9,3,=3,83=24,画出树状图并列出综合算式,2,6,=12,3,+12=15,15+,9,=24,2,6,12,3,15,9,24,+,+,综,合,算,式,3+2,6+9,=3+12+9,=15+9,=24,9,6,15,3,12,2,24,_,+,综,合,算,式,(9+6-3),2,=(15-3),2,=12,2,=24,9,+,6,=15,15,3,=12,12,2,=24,画出树状图并列出综合算式,综,合,算,式,画出树状图并列出综合算式,2,+,3,=5,9,5=4,4,6,=24,2,+,6,=8,9,3,=3,83=24,先说说运算顺序，再用递等式计算。,190,9018 97,2310,6633,217,44+66,11,84,+80020,40,在没有括号的 算式里，,既有乘、除法，又有加、减法，,要先算乘除法，再算加、减法。,先说说运算顺序，再用递等式计算。,821,21(40 28),821,(21,40 28),400,(10025),4,400,(10025,4),在含有括号的 算式里，,要先算括号里面的。,下面算式里的括号，哪些可以不写？为什么？,16,（,35-29,）,147+,（,389,）,（,78-14,）,4,1280-,（,16328,）,6,340+,（,193,）,-67,627-,（,8488,）,+125,22,37,229,+,7,191,162,522,+,378,892,369,+,1285,8,看树状图，列综合算式并计算。,动,脑,筋,在下面的数之间填上,+,、,、,或括号，使运算结果为,24,。,3 3 3 3 =24,5 5 5 5 =24,8 4 6 1 =24,13 5 7 4 =24,