问题
解答题
用简便方法计算. (1)21.9×8-8×1.9 (2)7
|
答案
(1)21.9×8-8×1.9
=(21.9-1.9)×8,
=20×8,
=160;
(2)7
+8.5+25 6
+6.11 6
=(7
+25 6
)+8.5+6.1,1 6
=10+14.6,
=24.6.
用简便方法计算. (1)21.9×8-8×1.9 (2)7
|
(1)21.9×8-8×1.9
=(21.9-1.9)×8,
=20×8,
=160;
(2)7
+8.5+25 6
+6.11 6
=(7
+25 6
)+8.5+6.1,1 6
=10+14.6,
=24.6.