问题
解答题
脱式计算.
1200-823+377
648÷8×5
720+1080÷6.
答案
(1)1200-823+377,
=1200-(800+23)+(400-23),
=1200-800-23+400-23,
=(1200-800+400)-(23+23),
=800-46,
=754;
(2)648÷8×5,
=81×5,
=405;
(3)720+1080÷6,
=720+180,
=900.