198+297+396+495(要简算过程)

问题描述:

198+297+396+495(要简算过程)

200+300+400+500-2-3-4-5=1386

(198+2)+(297+3)+(396+4)+(495+5)-(2+3+4+5)
=200+300+400+500-14
=1400-14
=1386

=200+300+400+500-2-3-4-5
=1400-14
=1386

95+96+97+98=2×(96+97)=386
1+2+3+4=10
10×100+386=1386

198+297+396+495
=495+396+495
=495x2+400-4
=990+400-4
=1386