用简便方法计算(1)56×12.5(2)14.6-(4.6+7.2

用简便方法计算(1)56×12.5(2)14.6-(4.6+7.2)(3)99×99+199.
2025-01-03 15:56:28
推荐回答(1个)
回答1:

(1)56×12.5,
=7×(8×12.5),
=7×100,
=700;

(2)14.6-(4.6+7.2),
=14.6-4.6-7.2,
=10-7.2,
=2.8;

(3)99×99+199,
=99×99+99+100,
=99×(99+1)+100,
=99×100+100,
=9900+100,
=10000.