数学[人教版]--五年级上--连乘、乘加、乘减ppt课件

?oU SoU?oU S吾U S?mbol?b?bmb?ml?:?bbmbbb?mbo?U?ml?2-?lb吾b?b?b?lb吾b bb?b?S?bbo lbb?b?b?b?0.450.18300?riar?X?X?Xia?yx?y85?y楷xyia r?楷r楷ir?XK楷?X?x?0.9楷ir?Xal?y楷xyia?aX?楷l?楷a X?iX100?Xi?r?rir 0.90.9100=0.81100=81（?MingMiU i?）100?1?n?iU?gi?110?b?riar?X?X?Xia?yx?y85?y楷xyia r?楷r楷ir?XK楷?X?x?0.9楷ir?Xal?y楷xyia?aX?楷l?楷a X?iX100?Xi?r?rir 0.8110+81=8.1+81=89.1（?MingMiU i?）0.90.9110=0.81110=89.1（?MingMiU i?）110?1?n?iU?g?.可以用可以用1010块的块的面积，加上面积，加上100100块的面积。块的面积。?1?g?nni1?inl1.?i1:?0?1,Mi0,?l1M?r1li1?l1M i1?.?nglM?1?1l?nl1M?1,?nl1M?ni?,.?i1:?0?1,Mi0,?l1M 1?1r?n,?1,li1?,?ni1 1r?i1?,?i?U.(1)4.07(1)4.078.68.69.1259.125(2)18.4(2)18.45.15.11.71.7(3)5.67(3)5.670.210.210.620.62?i1:?0?1,Mi0,?l1M?r1li1?l1M i1?.?nglM?1?1l?nl1M?1,?nl1M?ni?,.?i?1U?,1,?Mgl1,1 1?Mi1,?i?1U?,1,?i?1U?i?1U?i?1U?lM?lMMg?ni1:72 720.81+10.40.81+10.4=58.32+10.4=58.32+10.4=68.72=68.72 7.06 7.062.4-5.72.4-5.7=16.944-5.7=16.944-5.7=11.244=11.244 0.45 0.450.180.18300300=0.081=0.081300300=24.3=24.3?g?1?U 1?i?U?i1?ngi?1liMg?n,1?Mg?1,?,n?i1?i1?mb?b吾?mSoU?l?b?吾?m?b?U?b?m?U.0.70.71.2 1.21.2 1.20.70.7（0.80.80.50.5）0.4 0.80.4 0.8（0.50.50.40.4）（2.4+3.62.4+3.6）0.5 2.40.5 2.40.5+3.60.5+3.60.50.5?rMgni1r1?U?i1?,?Mg?1,?Mginr1,?ng1?i1?=0.65 0.65201201=0.65=0.65（200+1200+1）=0.65=0.65200+0.65200+0.65 0.25 0.254.784.784 4=0.25=0.254 44.78 4.78 SoU?b?l?吾?U b?oU?mb?b?b?b?.=+=+=1 4.781 4.784.78130 0.65130 0.65130.65130.65?Mg1r?n?.n,1?.n,iM?g?1?gi?,ig?,.0.0340.0340.50.50.6 1020.6 1020.450.454.84.80.25 2.330.25 2.330.50.54 41.51.5105 1.2105 1.22.5+0.82.5+0.82.52.5 Mgr1?n?Mg?n?M in?.n?1?,n?l1,?n?n?l1,l?1?nl1,?Urn?n?Mg?M285l?1iln n?1 i1gi1?.n?1i1lnl1?,iM?1?niMingMiU6?Mi?1.iU?n?1 iMl1,lM?nMi?1.iU1.30?1?M?i?l1l?,?1,?ni 1r?1,?M?i?g?1?28561.3017101.302223（?M?i）?M?1:?l1?nin22232223?M?i?ninU?ginU.