早教吧 育儿知识 作业答案 考试题库 百科 知识分享

用简便方法计算.240×35=260×40=308×20=400×90=48×90=160×80=

题目详情
用简便方法计算.
240×35= 260×40= 308×20=
400×90= 48×90= 160×80=
▼优质解答
答案和解析
(1)240×35
=24×10×5×7
=24×5×7×10
=120×7×10
=840×10
=8400;

(2)260×40
=26×4×100
=104×100
=10400;

(3)308×20
=308×2×10
=616×10
=6160;

(4)400×90
=4×9×1000
=36×1000
=36000;

(5)48×90
=48×9×10
=432×10
=4320;

(6)160×80
=16×8×100
=128×100
=12800.