问题
解答题
简便计算. 3.2×12.5×2.5 3.7×99+3.7
|
答案
①3.2×12.5×2.5
=(0.8×12.5)×(4×2.5)
=10×10
=100;
②3.7×99+3.7
=3.7×(99+1)
=3.7×100
=370;
③
×3 8
-7 4
×3 4
+3 8 3 8
=
×(3 8
-7 4
+1)3 4
=
×23 8
=
.3 4
简便计算. 3.2×12.5×2.5 3.7×99+3.7
|
①3.2×12.5×2.5
=(0.8×12.5)×(4×2.5)
=10×10
=100;
②3.7×99+3.7
=3.7×(99+1)
=3.7×100
=370;
③
×3 8
-7 4
×3 4
+3 8 3 8
=
×(3 8
-7 4
+1)3 4
=
×23 8
=
.3 4