想一想,算一算. 799999+79999+7999+799+79 22×43+22×32+75×18.
问题描述:
想一想,算一算.
799999+79999+7999+799+79
22×43+22×32+75×18.
答
(1)799999+79999+7999+799+79
=(800000-1)+(80000-1)+(8000-1)+(800-1)+(80-1)
=888880-5
=888875
(2)22×43+22×32+75×18
=22×(43+32)+75×18
=22×75+75×18
=(22+18)×75
=40×75
=3000