Question

4.5×4.9+0.45×300+0.0452.1怎么简便运算？

Answer 1

原式=4.5×4.9+4.5×30+4.5×0.021=4.5×(4.9+30+0.021)=4.5×34.921=157.1445
该题0.0452.1视作0.045×2.1

Answer 2

观察得4.5，0.45和0.045的关系，即4.5=0.45*10=0.045*100 ，原式等于0.045*100*4.9+0.045*10*300+0.045*2.1=0.045*（490+3000+2.1）=157.1445

Answer 3

4.5×4.9+0.45×300+0.045×2.1
=45×0.49+45×3+45×0.0021
=45×（0.49+3+0.0021）
=45×3.4521
=155.3445

Answer 4

4.5*4.9+0.45*300+0.045*2.1
=45*0.49+45*3+45*0.0021
=45*（0.49+3+0.0021）
=45*3.4521
=155.3445

Answer 5

=45×0.49+45×3+45×0.0021=45×（0.49+3+0.0021）=45×3.4521=155.3445