下面各题怎样简便就怎样计算.
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| (1)785+399 =785+400-1 =1185-1 =1184 (2)425+79+25 =425+25+79 =450+79 =529 (3)(63-25)×2 =63×2-25×2 =126-50 =76 (4)348+157-352 =505-352 =153 (5)3800-1900-1100 =3800-(1900+1100) =3800-3000 =800 (6)480+120÷6 =480+20 =500 (7)1038-496 =1038-500+4 =538-4 =534 (8)78÷(45-42) =78÷3 =26 (9)37×7-7+124 =259-7+124 =252+124 =376 |
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