簡便運算.
1874-298=
762+99= 789-101= 28×25=
125×32= 810÷45= 72×8×5= 480÷6÷8=
分析:(1)(2)(3)運用湊整法簡算;
(4)先把28分解7×4,再運用乘法結(jié)合律簡算;
(5)先把32分解成8×4,再運用乘法結(jié)合律簡算;
(6)運用商不變規(guī)律簡算;
(7)運用乘法結(jié)合律簡算;
(8)根據(jù)連續(xù)除以兩個數(shù),等于除以這兩個數(shù)的積簡算.
解答:解:(1)1874-298,
=1874-300+2,
=1574+2,
=1576;

(2)762+99,
=762+100-1,
=862-1,
=861;

(3)789-101,
=789-100-1,
=689-1,
=688;

(4)28×25,
=7×4×25,
=7×(4×25),
=7×100,
=700;

(5)125×32,
=125×(8×4),
=125×8×4,
=1000×4,
=4000;

(6)810÷45,
=(810÷9)÷(45÷9),
=90÷5,
=18;

(7)72×8×5,
=72×(8×5),
=72×40,
=2880;

(8)480÷6÷8,
=480÷(6×8),
=480÷48,
=10.
點評:完成本題要注意分析式中數(shù)據(jù),運用合適的簡便方法計算.
練習冊系列答案
相關(guān)習題

科目:小學數(shù)學 來源: 題型:解答題

簡便運算.
1874-298=
762+99=789-101=28×25=
125×32=810÷45=72×8×5=480÷6÷8=

查看答案和解析>>

同步練習冊答案