①(6+18)×125
=6×125+18×125
=750+2250
=3000;
②89×39+89
=89×(39+1)
=89×40
=3560;
③41×201
=41×200+41
=8200+41
=8241;
④79×33+79×67
=79×(33+67)
=79×100
=7900;
⑤57×11
=57×10+57
=570+57
=627;
⑥425×101
=425×100+425
=42500+425
=42925.
用简便方法计算. (6+18)×125 | 89×39+89 | 41×201 |
79×33+79×67 | 57×11 | 425×101. |