3 运动定律与简便运算
计算能简算的要用简便方法计算.
25×1.25×32×1.7= ; 78﹣4.5+22﹣= ;
5400﹣2940÷28×27= ; 20×(+﹣)= ;
()×5×4= ; 10÷[4﹣(÷+)]= .
直接写出得数.
0.44+++0.6 +2×2﹣2÷ (4﹣2)÷(1+2.4)
48200﹣156×720÷39 (3.06÷0.25+2.76)×0.2 [3÷(3﹣2.4×)]×0.2.
直接写出得数
0.9+99×0.9 ×2÷×2 36×25% 1.25×3.2×8 +0.75
( +)× 4.1×10.1 390×2%× 10÷10% +0.6+30%
脱式计算,能简算的要简算
9.81×0.1+0.5×98.1+0.049×981 2÷[(2﹣1.2)×+0.05]
100﹣32×0.125×0.25 [1﹣(﹣)]×.
观察下面备题的计算过程和结果,判断是否正确,对的画“√”错的画“×”,并改正过来.
(1)8×
=8=
=72
(2)14.3﹣
=14.3﹣()
=14.3﹣9.6
=4.7
(3)×84+101
=()×185
=
=
=39
(4)12.75﹣[6]
=12.75﹣[6]
=12.75﹣0
=12.75.
怎样简便怎样算
15×42﹣1308÷2 8.4﹣9.1÷1.3+5.8 4.7×68+53×6.8
2013× ÷8+÷+1÷8 7.1﹣0.45×(6.28+3.52)