用简便方法计算: 0.25×0.03×4 10.1×78 21.2×5+18.8×5 6.3+0.84+3.7+8.16.

问题描述:

用简便方法计算:
0.25×0.03×4           
10.1×78
21.2×5+18.8×5       
6.3+0.84+3.7+8.16.

(1)0.25×0.03×4 =(0.25×4)×0.03=1×0.03=0.03(2)10.1×78=100×78+0.1×78=7800+7.8=7807.8(3)21.2×5+18.8×5=(21.2+18.8)×5=40×5=200(4)6.3+0.84+3.7+8.16=6.3+0.84+3.7+8.16=(6.3+3.7)+(0.8...