简便方法
7.69x9.8
=7.69x(10-0.2)
=7.69x10-7.69x0.2
=76.9-1.538
=75.362
7.69×9.8=7.69×(10-0.2)
=76.9-15.238=61.662
7.69x9.8简便方法?
7.69×9.8
=7.69×(10-0.2)
=7.69×10-7.69×0.2
=76.9-1.538
=75.362
简便运算主要是通过交换律、结合律,将相关数字交换结合,凑成整数,达到速算目的。
7.69×9.8
=7.69×(10-0.2)
=7.69×10-7.69×0.2
=76.9-1.538
=75.362