【题目】
用简便方法计算. 45×102
38+817+2617+5825.28-11.65+34.72-38.3536×(
1112+124-38)
(1)45×102
=45×(100+2),
=45×100+45×3,
=4500+90,
=4590.
(2)38+817+2617+58
=(38+58)+(817+2617),
=1+3417,
=1+2,
=3;
(3)25.28-11.65+34.72-38.35
=(25.28+34.72)-(11.65+38.35),
=60-50,
=10;
(4)36×(1112+124-38)
=36×1112+36×124-36×38,
=33+112-1312,
=21.