35x68 68x65简便计算方法怎么算快点!急!

2025-03-30 17:01:54
推荐回答(2个)
回答1:

(1):35x68
=(30+5)X(70-2)

=30X70-30X2+5X70-5X2
=2100-60+350-10
=2380
(2):68x65
=(70-2)X(70-5)
=70X70-70X5-2X70+2X5
=4900-350-140+10
=4420

回答2:

35x68+68x65
=68x(35+65)
=68x100
=6800