小学数学二年级23连加连减和加减混合14维语ppt课件.ppt
1. ,(1)35+32 (2)32+29,(3)78-24 (4)52-27,2. ,25+34=,59,59,+22=81,81,+11=92,92-54=,38,38-18=,20,20,+52=72,72-54=,18,18,-18=0,1.100 - . .2. .,- ,1 38+14+32=, ,38+14+32=84,38+14=52,52+32=84, , , ,(1)43+15+34 (2)18+2+56,- ,1 58-14-32=, ,58-14-32=12,58-14=44,44-32=12, ,- , , ,(1)89-56-6 (2)67-34-17, , , , 45 ,12了 ,了 , 45 12 45-12 45-12+2.,45-12+2=,45-12+2=35,45-12=33,33+2=35, , , ,(1)89-56+6 (2)67-34+17,2. ,47+12-3476-25-3240-17+3525-6+5678-35-23,76-32-2535-17+4056-6+2547-34+1278-23-35, ,2-1- 24 1- 2- 25 ,24+2550(), :2425 50,2. : 28-21+49, 28+4980 80-21 60,28-21 1010+49 60 ,- ,1.- .2. .3. .,70-40+25,77-23+5, : ,56-30+23,23+23+5,67-23-5,25-40+70,77+5-23,56+23-30,67-5-23,5+23+23,70-40+25,77-23+5,56-30+23,23+23+5,67-23-5,25-40+70,77+5-23,56+23-30,67-5-23,5+23+23, : , 70 .,23+9-1,23+9-1,76-45+62,88-7-11,23+19+31,32-9+61,45+5-23,25-5+61, : , : - , 21 .,9,7,4,11,3,8,119+55+25=99 19+40+30=89 25+34+30=89 24+45+30=99 48+36+5=89 17+18+64=99 24+48+17=89 45+36+18=99 30+5+64=992 27 5 82,5-(29-),328+11+59=98493 62 0 4 42 0539+8=47 47-20=27 56+8=64 64-20=44 18+8=26 26-20=6,6 - (32-)131+52 23+41+29 98-17,220+1230。329+42=70(), 70 。 100-70=30() 30 。( )100-29 70 70 70-4230 30 .,7-(34-)141 29 92 19231 5 60 68387 55 54 3 69 8 62 65 96 36 97 46 65 36 96 4 = ,551+38 90 641-13=28()722-15=7()839 96 63 29 59 36 50 41 56 73 80 75 33 87 11 48 32 26 66 30 18 23 43 91,-,