脱式计算,能简算的简算. 4.2-1.38+5.8-3.62 0.125×0.25×32 2÷2/3-2/3÷2 90.5×99+90.5.
问题描述:
脱式计算,能简算的简算.
4.2-1.38+5.8-3.62
0.125×0.25×32
2÷
-2 3
÷2 2 3
90.5×99+90.5.
答
(1)4.2-1.38+5.8-3.62
=4.2+5.8-(1.38+3.62)
=10-5
=5;
(2)0.125×0.25×32
=0.125×0.25×8×4
=(0.125×8)×(0.25×4)
=1;
(3)2÷
-2 3
÷2 2 3
=2×
-3 2
×2 3
1 2
=3-
1 3
=2
;2 3
(4)90.5×99+90.5
=90.5×(99+1)
=90.5×100
=9050;
故答案为2.8;1;2
;9050.2 3