简便运算(1)35×18-7×35-35(2)99×9798(3)9.99×22.2+33.3×3.34(4)13+115+135+163+199+1143.-数学
题文
简便运算
|
答案
(1)
=
=
=6; (2)99×
=(98+1)×
=98×
=97+
=97
(3)9.99×22.2+33.3×3.34, =19.98×11.1+11.1×10.02, =(19.98+10.02)×11.1, =30×11.1, =333; (4)
=[(1- |
题文
简便运算
|
答案
(1)
=
=
=6; (2)99×
=(98+1)×
=98×
=97+
=97
(3)9.99×22.2+33.3×3.34, =19.98×11.1+11.1×10.02, =(19.98+10.02)×11.1, =30×11.1, =333; (4)
=[(1- |