角1二课时度分秒运算.ppt

度、分、秒的计算,例1：填空（1）34.50=0/（2）112.270=0/解：（1）34.50=340+0.50=340+0.560/=340+30/=34030/（2）112.270=1120+0.2760/=1120+16.2/=1120+16/+0.260/=112016/12/,34,30,112,16,12,题型一：角度的换算,例2、把下列各题结果化成度72036/(2)37014/24/解:(1)72036/=720+36/=720+(3660)0=720+0.60=72.60,(2)37014/24/=370+14/+24/=370+14/+(2460)/=370+14/+0.4/=370+14.4/=370+(14.460)0=370+0.240=37.240,例3、加减法计算,解:(1)原式=(12+45)0+(36+24)/+(56+35)/=570+60/+91/=570+61/+31/=580+1/+31/=5801/31/,题型二：角度的加减法运算,(1)12036/56/+45024/35/,(2)79045/61048/49/,(2)79045/61048/49/解:原式=79044/60/61048/49/=780104/60/61048/49/=(78-61)0(104-48)/(60-49)/=17056/11/,例4：计算,=825936,解（1）,=3738+4521.6,=3738+452136,解,=3236,=4660-1424,=（46-14）（60-24）,=（37+45）（38+21）36,例6、乘除法运算(3)21031/27/3(4)63021/39/3(5)10606/25/5解:原式=(213)0(313)/(273)/=63093/81/=63094/21/=64034/21/,题型三：角度的乘除法运算,(4)63021/39/3解:原式=(633)0(213)/(393)/=2107/13/(5)10606/25/5解:原式=(1065)0(65)/(255)/=210(665)/(255)/=21013/(855)/=21013/17/,题型三：角度的乘除法运算,例7：把一个周角7等分,每一份角是多少度?（精确到分）,解:,3607=,51+,37,=51+,1807,51+,26,即5126,1.计算:,(1)4835+1745,(2)15205,=6620,=7640,=6580=6620,=75100=7640,比一比,看谁反应快:,(3)48181745,=3033,=4778-1745=3033,(4)36011,（1）10.26=（2）0.25=（3）62.3=（4）6045=（5）108.8=（6）90452332=（7）7742+3025=（8）89185736=（9）4030+303030=（10）21324=（11）90153=（12）3632256=（13）48.126=,练一练,101536,15,6218,60.75,10848,443628,1087,3142,7130,868,305,2191430,8112,小结与归纳,1度、分、秒都是60进制，逢60进1；,加减法要将度与度、分与分、秒与秒分别加减，分秒相加逢60要进位，相减时要借1当