Question

69×88-78的简便计算

Answer 1

69×88-78的简便计算
69×88-78
=88*70-88-78
=6160-166
=5994

Answer 2

69×88-78
=(68+1)×(78+10)-78
=68×78+68×10+1×78+10-78
=68×78+68×10+10
=68×(78+10）+10
=68×88+10
=（70-2）×（90-2）+10
=6300-140-180+4+10
=6300-320+10+4
=6000+300-310+4
=6000-10+4
=5994