用简便方法将计算 1. 98-32-28 2.156-19-81 3.217-65-135 4.345-66-34 5.205+87+13 6.398-163-137
问题描述:
用简便方法将计算 1. 98-32-28 2.156-19-81 3.217-65-135 4.345-66-34 5.205+87+13 6.398-163-137
答
1.98-32-28
=98-(32+28)
=98-60
=38
2.156-19-81
=156-(19+81)
=156-100
=56
3.217-65-135
=217-(65+135)
=217-200
=17
4.345-66-34
=345-(66+34)
=345-100
=245
5.205+87+13
=205+(87+13)
=205+100
=305
6.398-163-137
=398-(136+137)
=398-300
=98