5.5 640 0.9 0.8 12 30 0 90 5 7.8 4.3 5.2 6
1
40 10
0.64 24 0.12 0.5 3.8 3.6 77.2 27 110 3.18 9 10 2.7 1.9
2 13
120 1.1
4.2 78.5 113.04 0.0064 25.12 1.75 8 80
分析:依据四则运算计算方法,以及比与分数,除式,百分数互化求解.
解答:2.1+3.4=5.5;720-80=640;2.6-1.7=0.9;1.4-0.6=0.8;0.3×40=12; 1.25×3×8=30;3.8×0=0;0.9+99×0.9=90;7÷1.4=5;390×0.02=7.8;2.5+1.8=4.3;6.5×4×0.2=5.2;8×
=6
;
÷
=1
;44÷
=40;4×(0.6+1.9)=10;
+
=
;0.9-0.26=0.64;14.5+9.5=24;(0.18+0.9)÷9=0.12;18÷36=0.5;1.9×4×0.5=3.8;7.2÷8×4=3.6;78-0.8=77.2;62-35=27;20×5.5=110;1.68+1.5=3.18;
×12=9;8.3+1.7=10;11.3-8.6=2.7;2.4-0.5=1.9;
÷
=
;
+
=2;3.25×4=13;
÷2=
;
÷3=
;24×5=120;0.77+0.33=1.1;
×
=
;12.6÷3=4.2;3.14×25=78.5;3.14×36=113.04;0.08
2=0.0064;8л=25.12;1.4:1.75=
=8÷10=80%.故答案依次为:5.5,640,0.9,0.8,12,30,0,90,5,7.8,4.3,5.2,6
,1
,40,10,
0.64,24,0.12,0.5,3.8,3.6,77.2,27,110,3.18,9,10,2.7,1.9,
,2,13,
,
,120,1.1,
,4.2,78.5,113.04,0.0064,25.12,1.75,8,80,.
点评:本题主要考查学生四则运算计算能力.