问题
填空题
5个7的和比30多______,比4个7多______,比8个7少______.
答案
7×5-30
=35-30
=5;
7×5-7×4
=35-28
=7;
7×8-7×5
=56-35
=21;
答:5个7的和比30多5,比4个7多7,比8个7少21.
故答案为:5;7;21.
5个7的和比30多______,比4个7多______,比8个7少______.
7×5-30
=35-30
=5;
7×5-7×4
=35-28
=7;
7×8-7×5
=56-35
=21;
答:5个7的和比30多5,比4个7多7,比8个7少21.
故答案为:5;7;21.