内容正文:
单元 3 第 1 课时 加法交换律和加法结合律(教材 P17 ~ 18)
4 年级 下 R
36 + 64 = 25 + 45 = 83 + 17 = 36 + 28 =
72 + 11 = 42 + 53 = 28 + 42 = 46 + 54 =
33 + 14 = 36 - 28 = 17 + 82 = 100 - 36 =
73 + 137 = 77 - 23 = 15 + 55 = 143 + 57 =
85 + 15 = 46 + 54 = 68 + 332 = 90 + 110 =
125 + 275 = 220 + 140 = 130 + 770 = 45 + 99 =
168 + 132 = 45 + 255 = 77 + 123 = 800 - 175 =
541 + 59 = 312 + 88 = 154 + 86 = 430 + 270 =
53 + 147 = 780 - 120 = 548 - 248 = 640 + 390 =
378 + 229 + 122 155 + 64 + 245 + 36 427 + 569 + 373
88 + 139 + 212 + 361 755 + 533 + 167 + 245 75 + 469 + 125
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单元 3 第 2 课时 加法运算律的应用(1)(教材 P20)
4 年级 下 R
79 + 21 = 77 + 23 = 45 + 25 = 413 + 57 =
68 + 35 = 100 - 48 = 52 + 48 = 38 + 26 =
47 + 16 = 81 + 19 = 35 + 25 = 66 + 34 =
71 + 29 = 148 + 52 = 632 + 68 = 800 - 270 =
342 + 158 = 22 + 77 = 45 + 26 = 53 + 84 =
90 - 45 = 152 + 128 = 37 + 92 = 144 + 321 =
243 + 57 = 83 + 17 = 33 + 67 = 28 + 72 =
11 + 58 = 66 + 32 = 148 + 532 = 673 - 173 =
75 + 425 = 180 - 90 = 572 - 172 = 346 + 154 =
308 + 319 + 292 178 + 57 + 22 + 543 123 + 569 + 77 + 31
321 + 254 + 179 + 346 295 + 88 + 12 408 + 56 + 92 + 144
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单元 3 第 3 课时 加法运算律的应用(2)(教材 P20)
4 年级 下 R
32 + 68 = 68 + 32 = 12 + 88 = 88 + 12 =
49 + 51 = 51 + 49 = 85 + 15 = 36 + 44 =
63 + 56 = 25 + 48 = 47 + 23 = 70 - 47 =
35 + 24 = 58 + 45 = 25 + 45 = 32 + 48 =
260 + 40 = 88 + 112 = 190 + 110 = 34 + 56 =
11 + 39 = 105 + 45 = 25 + 85 = 125 + 275 =
328 + 172 = 137 + 33 = 768 + 52 = 328 + 22 =
432 + 168 = 229 + 71 = 362 + 138 = 147 + 53 =
417 + 245 = 720 - 148 = 513 + 427 = 460 - 280 =
182 + 196 + 118 238 + 147 + 62 + 253 478 + 96 + 122
125 + 56 + 144 + 75 345 + 20 + 280 + 55 31 + 115 + 169
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单元 3 第 4 课时 减法的性质(教材 P21)
4 年级 下 R
25 + 75 = 42 + 58 = 15 + 35 = 100 - 53 =
33 + 67 = 71 +