用简便方法计算.45×1024.93×101-4.9363×(

用简便方法计算.45×1024.93×101-4.9363×( 4 9 + 5 7 + 8 21 )400÷1.25÷8.
2025-04-18 15:42:29
推荐回答(1个)
回答1:

(1)45×102,
=45×(100+2),
=45×100+45×2,
=4500+90,
=4590;

(2)4.93×101-4.93,
=4.93×(101-1),
=4.93×100,
=493;

(3)63×(
4
9
+
5
7
+
8
21
),
=63×
4
9
+63×
5
7
+63×
8
21

=28+45+24,
=73+24,
=97;

(4)400÷1.25÷8,
=400÷(1.25×8),
=400÷10,
=40.