简算0.125×3.2×0.254.8×100.156.5×99+56.57.09×10.8-0.8×7.09．

Question

简算
0.125×3.2×0.25
4.8×100.1
56.5×99+56.5
7.09×10.8-0.8×7.09．

Answer 1

①0.125×3.2×0.25
=0.125×（8×0.4）×0.25
=（0.125×8）×（0.4×0.25）
=1×0.1
=0.1

②4.8×100.1
=4.8×（100+0.1）
=4.8×100+4.8×0.1
=480+0.48
=480.48

③56.5×99+56.5
=56.5×（99+1）
=56.5×100
=5650

④7.09×10.8-0.8×7.09
=7.09×（10.8-0.8）
=7.09×10
=70.9