Question

28×1.25+3.2×12.5+0.4×125简便计算？

Answer 1

题目中有1.25，12.5，125。可把它们经放大或缩小后变成相同的数后再运算:
28ⅹ1.25+3.2x12.5+0.4ⅹ125
=2.8ⅹ10x1.25+3.2x12.5+0.4x12.5x10
=（2.8+3.2+4）x12.5
=10x12.5
=125

Answer 2

回答：
28×1.25+3.2×12.5+0.4×125
=28×1.25+32×1.25+40×1.25
=1.25×（28+32+40）
=1.25×100
=125
运用了乘法分配律

Answer 3

28x1.25+3.2x12.5+0.4x125简便计算为：
=28x1.25+3.2x12.5+0.4x125
=20x1.25+8x1.25+(8x12.5x0.4)+0.4x125
=25+10+40+50
=125
或者
=28x1.25+3.2x12.5+0.4x125
=28x1.25+3.2x10x12.5/10+0.4x100x125/100
=28x1.25+32x1.25+40x1.25
=1.25x(28+32+40)
=1.25x100
=125

Answer 4

28×1.25+3.2×12.5+0.4×125
＝28×1.25+32×1.25+40×1.25
=(28+32+40)×1.25
=100×1.25
=125

Answer 5

28×1.25+3.2×12.5+0.4×125
=2.8×12.5+3.2×12.5+50
=12.5×（2.8+3.2）+50
=12.5×6+50
=75+50
=125
希望能帮到你！