问题
解答题
脱式计算,能简算的要简算. (1)3.6-2.8+7.4-7.2; (2)
(3)(5÷
(4)
|
答案
(1)3.6-2.8+7.4-7.2
=(3.6+7.4)-(2.8+7.2)
=11-10
=1
(2)
×101-37 100 37 100
=
×(101-1)37 100
=
×10037 100
=37
(3)(5÷
-5 6
÷5)÷5 6 5 18
=(6-
)×1 6 18 5
=
×35 6 18 5
=21
(4)
×7.7+3.3×0.8-80%4 5
=0.8×(7.7+3.3-1)
=0.8×10
=8